4.9.62: intermittent flicker after upgrade from 4.9.61

4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Hi!

Hopefully the right addressee.

Encountered two bad backports which cause screen-flicker.
dmesg shows:

...
[drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
[drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
[drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
[drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
...

CPU: Intel Core i3 (Clarkdale/Ironlake)

The backports are:

- diff --git a/drivers/gpu/drm/i915/intel_pm.c
b/drivers/gpu/drm/i915/intel_pm.c
    index 49de476..277a802 100644
- diff --git a/drivers/gpu/drm/i915/intel_drv.h
b/drivers/gpu/drm/i915/intel_drv.h
    index a19ec06..3ce9ba3 100644

After reversing them the flicker is gone, no more messages in dmesg. All
else OK so far.

I have also reported this here:

 https://bugs.freedesktop.org/show_bug.cgi?id=103796

So long!

Rainer Fiebig


-- 
The truth always turns out to be simpler than you thought.
Richard Feynman

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> Hi!
> 
> Hopefully the right addressee.
> 
> Encountered two bad backports which cause screen-flicker.
> dmesg shows:
> 
> ...
> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> ...
> 
> CPU: Intel Core i3 (Clarkdale/Ironlake)
> 
> The backports are:
> 
> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> b/drivers/gpu/drm/i915/intel_pm.c
>     index 49de476..277a802 100644
> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h
>     index a19ec06..3ce9ba3 100644
> 
> After reversing them the flicker is gone, no more messages in dmesg. All
> else OK so far.

So which commit was the one that caused the problem?  I will be glad to
revert it.

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>> Hi!
>>
>> Hopefully the right addressee.
>>
>> Encountered two bad backports which cause screen-flicker.
>> dmesg shows:
>>
>> ...
>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>> ...
>>
>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>
>> The backports are:
>>
>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>> b/drivers/gpu/drm/i915/intel_pm.c
>>     index 49de476..277a802 100644
>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> b/drivers/gpu/drm/i915/intel_drv.h
>>     index a19ec06..3ce9ba3 100644
>>
>> After reversing them the flicker is gone, no more messages in dmesg. All
>> else OK so far.
> 
> So which commit was the one that caused the problem?  I will be glad to
> revert it.
> 
> thanks,
> 
> greg k-h
> 
>

I started by reverting the more complex one first ("index
49de476..277a802100644"). But the kernel wouldn't compile then.

So I also reverted "index a19ec06..3ce9ba3 100644". After that the
kernel compiled just fine and the problems were gone (still are).

I haven't yet tried it vice versa - it was a bit late yesterday. But
I'll give it a try somewhat later today and let you know.

Personally, I could live without *both* of them.

So long!
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> Greg KH wrote:
> > On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> >> Hi!
> >>
> >> Hopefully the right addressee.
> >>
> >> Encountered two bad backports which cause screen-flicker.
> >> dmesg shows:
> >>
> >> ...
> >> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> >> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> >> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> >> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> >> ...
> >>
> >> CPU: Intel Core i3 (Clarkdale/Ironlake)
> >>
> >> The backports are:
> >>
> >> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> >> b/drivers/gpu/drm/i915/intel_pm.c
> >>     index 49de476..277a802 100644
> >> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >> b/drivers/gpu/drm/i915/intel_drv.h
> >>     index a19ec06..3ce9ba3 100644
> >>
> >> After reversing them the flicker is gone, no more messages in dmesg. All
> >> else OK so far.
> > 
> > So which commit was the one that caused the problem?  I will be glad to
> > revert it.
> > 
> > thanks,
> > 
> > greg k-h
> > 
> >
> 
> I started by reverting the more complex one first ("index
> 49de476..277a802100644"). But the kernel wouldn't compile then.

What git commit id is that?  I don't see those ids in the 4.9-stable
tree.

> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> kernel compiled just fine and the problems were gone (still are).

Same here, what git commit id was this?

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>> Greg KH wrote:
>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>> Hi!
>>>>
>>>> Hopefully the right addressee.
>>>>
>>>> Encountered two bad backports which cause screen-flicker.
>>>> dmesg shows:
>>>>
>>>> ...
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>> ...
>>>>
>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>
>>>> The backports are:
>>>>
>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>     index 49de476..277a802 100644
>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>     index a19ec06..3ce9ba3 100644
>>>>
>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>> else OK so far.
>>>
>>> So which commit was the one that caused the problem?  I will be glad to
>>> revert it.
>>>
>>> thanks,
>>>
>>> greg k-h
>>>
>>>
>>
>> I started by reverting the more complex one first ("index
>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> 
> What git commit id is that?  I don't see those ids in the 4.9-stable
> tree.
> 
>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>> kernel compiled just fine and the problems were gone (still are).
> 
> Same here, what git commit id was this?
> 
> thanks,
> 
> greg k-h
> 

Please wait a moment. I'm checking whether I've made a mistake here.

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

[-- Attachment #1: Type: text/plain, Size: 2197 bytes --]

Greg KH wrote:
> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>> Greg KH wrote:
>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>> Hi!
>>>>
>>>> Hopefully the right addressee.
>>>>
>>>> Encountered two bad backports which cause screen-flicker.
>>>> dmesg shows:
>>>>
>>>> ...
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>> ...
>>>>
>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>
>>>> The backports are:
>>>>
>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>     index 49de476..277a802 100644
>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>     index a19ec06..3ce9ba3 100644
>>>>
>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>> else OK so far.
>>>
>>> So which commit was the one that caused the problem?  I will be glad to
>>> revert it.
>>>
>>> thanks,
>>>
>>> greg k-h
>>>
>>>
>>
>> I started by reverting the more complex one first ("index
>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> 
> What git commit id is that?  I don't see those ids in the 4.9-stable
> tree.
> 
>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>> kernel compiled just fine and the problems were gone (still are).
> 
> Same here, what git commit id was this?
> 
> thanks,
> 
> greg k-h
> 

OK, no mistake. IIRC, I took the patches (and the IDs) from the
changelog for patch-4.9.62. I've attached both, so you can check yourself.

I've also applied a freshly downloaded patch-4.9.62 to a freshly
expanded 4.9 and re-compiled. The flicker is there. I haven't yet
reverted the two patches but I'm confident that after having done so the
flicker will be gone. If not I'll let you know.

As a good news: 4.14 is *not* affected. So to me it seems those two
patches are part of sort of a package and can not be backported alone.

So long!
Rainer Fiebig

[-- Attachment #2: patch-4.9.62_49de476 --]
[-- Type: text/plain, Size: 3910 bytes --]

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 49de476..277a802 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -27,6 +27,7 @@
 
 #include <linux/cpufreq.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_atomic_helper.h>
 #include "i915_drv.h"
 #include "intel_drv.h"
 #include "../../../platform/x86/intel_ips.h"
@@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
 				 const struct intel_crtc *intel_crtc,
 				 int level,
 				 struct intel_crtc_state *cstate,
-				 struct intel_plane_state *pristate,
-				 struct intel_plane_state *sprstate,
-				 struct intel_plane_state *curstate,
+				 const struct intel_plane_state *pristate,
+				 const struct intel_plane_state *sprstate,
+				 const struct intel_plane_state *curstate,
 				 struct intel_wm_level *result)
 {
 	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
@@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
 	struct intel_pipe_wm *pipe_wm;
 	struct drm_device *dev = state->dev;
 	const struct drm_i915_private *dev_priv = to_i915(dev);
-	struct intel_plane *intel_plane;
-	struct intel_plane_state *pristate = NULL;
-	struct intel_plane_state *sprstate = NULL;
-	struct intel_plane_state *curstate = NULL;
+	struct drm_plane *plane;
+	const struct drm_plane_state *plane_state;
+	const struct intel_plane_state *pristate = NULL;
+	const struct intel_plane_state *sprstate = NULL;
+	const struct intel_plane_state *curstate = NULL;
 	int level, max_level = ilk_wm_max_level(dev), usable_level;
 	struct ilk_wm_maximums max;
 
 	pipe_wm = &cstate->wm.ilk.optimal;
 
-	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
-		struct intel_plane_state *ps;
+	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
+		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
 
-		ps = intel_atomic_get_existing_plane_state(state,
-							   intel_plane);
-		if (!ps)
-			continue;
-
-		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
 			pristate = ps;
-		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
+		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
 			sprstate = ps;
-		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
+		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
 			curstate = ps;
 	}
 
@@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
 	if (pipe_wm->sprites_scaled)
 		usable_level = 0;
 
-	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
-			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
-
 	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
-	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
+	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
+			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
 
 	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
 		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
@@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
 
 	ilk_compute_wm_reg_maximums(dev, 1, &max);
 
-	for (level = 1; level <= max_level; level++) {
-		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
+	for (level = 1; level <= usable_level; level++) {
+		struct intel_wm_level *wm = &pipe_wm->wm[level];
 
 		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
 				     pristate, sprstate, curstate, wm);
@@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
 		 * register maximums since such watermarks are
 		 * always invalid.
 		 */
-		if (level > usable_level)
-			continue;
-
-		if (ilk_validate_wm_level(level, &max, wm))
-			pipe_wm->wm[level] = *wm;
-		else
-			usable_level = level;
+		if (!ilk_validate_wm_level(level, &max, wm)) {
+			memset(wm, 0, sizeof(*wm));
+			break;
+		}
 	}
 
 	return 0;

[-- Attachment #3: patch-4.9.62_a19ec06 --]
[-- Type: text/plain, Size: 399 bytes --]

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a19ec06..3ce9ba3 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
 
 struct intel_pipe_wm {
 	struct intel_wm_level wm[5];
-	struct intel_wm_level raw_wm[5];
 	uint32_t linetime;
 	bool fbc_wm_enabled;
 	bool pipe_enabled;

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
> Greg KH wrote:
> > On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> >> Greg KH wrote:
> >>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> >>>> Hi!
> >>>>
> >>>> Hopefully the right addressee.
> >>>>
> >>>> Encountered two bad backports which cause screen-flicker.
> >>>> dmesg shows:
> >>>>
> >>>> ...
> >>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> >>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> >>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> >>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> >>>> ...
> >>>>
> >>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
> >>>>
> >>>> The backports are:
> >>>>
> >>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> >>>> b/drivers/gpu/drm/i915/intel_pm.c
> >>>>     index 49de476..277a802 100644
> >>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >>>> b/drivers/gpu/drm/i915/intel_drv.h
> >>>>     index a19ec06..3ce9ba3 100644
> >>>>
> >>>> After reversing them the flicker is gone, no more messages in dmesg. All
> >>>> else OK so far.
> >>>
> >>> So which commit was the one that caused the problem?  I will be glad to
> >>> revert it.
> >>>
> >>> thanks,
> >>>
> >>> greg k-h
> >>>
> >>>
> >>
> >> I started by reverting the more complex one first ("index
> >> 49de476..277a802100644"). But the kernel wouldn't compile then.
> > 
> > What git commit id is that?  I don't see those ids in the 4.9-stable
> > tree.
> > 
> >> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> >> kernel compiled just fine and the problems were gone (still are).
> > 
> > Same here, what git commit id was this?
> > 
> > thanks,
> > 
> > greg k-h
> > 
> 
> OK, no mistake. IIRC, I took the patches (and the IDs) from the
> changelog for patch-4.9.62. I've attached both, so you can check yourself.
> 
> I've also applied a freshly downloaded patch-4.9.62 to a freshly
> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
> reverted the two patches but I'm confident that after having done so the
> flicker will be gone. If not I'll let you know.
> 
> As a good news: 4.14 is *not* affected. So to me it seems those two
> patches are part of sort of a package and can not be backported alone.
> 
> So long!
> Rainer Fiebig

> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 49de476..277a802 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -27,6 +27,7 @@
>  
>  #include <linux/cpufreq.h>
>  #include <drm/drm_plane_helper.h>
> +#include <drm/drm_atomic_helper.h>
>  #include "i915_drv.h"
>  #include "intel_drv.h"
>  #include "../../../platform/x86/intel_ips.h"
> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>  				 const struct intel_crtc *intel_crtc,
>  				 int level,
>  				 struct intel_crtc_state *cstate,
> -				 struct intel_plane_state *pristate,
> -				 struct intel_plane_state *sprstate,
> -				 struct intel_plane_state *curstate,
> +				 const struct intel_plane_state *pristate,
> +				 const struct intel_plane_state *sprstate,
> +				 const struct intel_plane_state *curstate,
>  				 struct intel_wm_level *result)
>  {
>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>  	struct intel_pipe_wm *pipe_wm;
>  	struct drm_device *dev = state->dev;
>  	const struct drm_i915_private *dev_priv = to_i915(dev);
> -	struct intel_plane *intel_plane;
> -	struct intel_plane_state *pristate = NULL;
> -	struct intel_plane_state *sprstate = NULL;
> -	struct intel_plane_state *curstate = NULL;
> +	struct drm_plane *plane;
> +	const struct drm_plane_state *plane_state;
> +	const struct intel_plane_state *pristate = NULL;
> +	const struct intel_plane_state *sprstate = NULL;
> +	const struct intel_plane_state *curstate = NULL;
>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>  	struct ilk_wm_maximums max;
>  
>  	pipe_wm = &cstate->wm.ilk.optimal;
>  
> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> -		struct intel_plane_state *ps;
> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>  
> -		ps = intel_atomic_get_existing_plane_state(state,
> -							   intel_plane);
> -		if (!ps)
> -			continue;
> -
> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>  			pristate = ps;
> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>  			sprstate = ps;
> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>  			curstate = ps;
>  	}
>  
> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>  	if (pipe_wm->sprites_scaled)
>  		usable_level = 0;
>  
> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> -
>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>  
>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>  
>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>  
> -	for (level = 1; level <= max_level; level++) {
> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> +	for (level = 1; level <= usable_level; level++) {
> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>  
>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>  				     pristate, sprstate, curstate, wm);
> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>  		 * register maximums since such watermarks are
>  		 * always invalid.
>  		 */
> -		if (level > usable_level)
> -			continue;
> -
> -		if (ilk_validate_wm_level(level, &max, wm))
> -			pipe_wm->wm[level] = *wm;
> -		else
> -			usable_level = level;
> +		if (!ilk_validate_wm_level(level, &max, wm)) {
> +			memset(wm, 0, sizeof(*wm));
> +			break;
> +		}
>  	}
>  
>  	return 0;

> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a19ec06..3ce9ba3 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>  
>  struct intel_pipe_wm {
>  	struct intel_wm_level wm[5];
> -	struct intel_wm_level raw_wm[5];
>  	uint32_t linetime;
>  	bool fbc_wm_enabled;
>  	bool pipe_enabled;

Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
4.9.62.

I've cc:ed the authors of that patch now.

Maarten, any hints?  Should I revert this from 4.9-stable, or was there
a follow-on patch that resolved this issue in mainline?

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>> Greg KH wrote:
>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>> Greg KH wrote:
>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>> Hi!
>>>>>>
>>>>>> Hopefully the right addressee.
>>>>>>
>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>> dmesg shows:
>>>>>>
>>>>>> ...
>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>> ...
>>>>>>
>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>
>>>>>> The backports are:
>>>>>>
>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>     index 49de476..277a802 100644
>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>
>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>> else OK so far.
>>>>>
>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>> revert it.
>>>>>
>>>>> thanks,
>>>>>
>>>>> greg k-h
>>>>>
>>>>>
>>>>
>>>> I started by reverting the more complex one first ("index
>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>
>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>> tree.
>>>
>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>> kernel compiled just fine and the problems were gone (still are).
>>>
>>> Same here, what git commit id was this?
>>>
>>> thanks,
>>>
>>> greg k-h
>>>
>>
>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>
>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>> reverted the two patches but I'm confident that after having done so the
>> flicker will be gone. If not I'll let you know.
>>
>> As a good news: 4.14 is *not* affected. So to me it seems those two
>> patches are part of sort of a package and can not be backported alone.
>>
>> So long!
>> Rainer Fiebig
> 
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index 49de476..277a802 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -27,6 +27,7 @@
>>  
>>  #include <linux/cpufreq.h>
>>  #include <drm/drm_plane_helper.h>
>> +#include <drm/drm_atomic_helper.h>
>>  #include "i915_drv.h"
>>  #include "intel_drv.h"
>>  #include "../../../platform/x86/intel_ips.h"
>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>  				 const struct intel_crtc *intel_crtc,
>>  				 int level,
>>  				 struct intel_crtc_state *cstate,
>> -				 struct intel_plane_state *pristate,
>> -				 struct intel_plane_state *sprstate,
>> -				 struct intel_plane_state *curstate,
>> +				 const struct intel_plane_state *pristate,
>> +				 const struct intel_plane_state *sprstate,
>> +				 const struct intel_plane_state *curstate,
>>  				 struct intel_wm_level *result)
>>  {
>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>  	struct intel_pipe_wm *pipe_wm;
>>  	struct drm_device *dev = state->dev;
>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>> -	struct intel_plane *intel_plane;
>> -	struct intel_plane_state *pristate = NULL;
>> -	struct intel_plane_state *sprstate = NULL;
>> -	struct intel_plane_state *curstate = NULL;
>> +	struct drm_plane *plane;
>> +	const struct drm_plane_state *plane_state;
>> +	const struct intel_plane_state *pristate = NULL;
>> +	const struct intel_plane_state *sprstate = NULL;
>> +	const struct intel_plane_state *curstate = NULL;
>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>  	struct ilk_wm_maximums max;
>>  
>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>  
>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>> -		struct intel_plane_state *ps;
>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>  
>> -		ps = intel_atomic_get_existing_plane_state(state,
>> -							   intel_plane);
>> -		if (!ps)
>> -			continue;
>> -
>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>  			pristate = ps;
>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>  			sprstate = ps;
>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>  			curstate = ps;
>>  	}
>>  
>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>  	if (pipe_wm->sprites_scaled)
>>  		usable_level = 0;
>>  
>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>> -
>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>  
>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>  
>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>  
>> -	for (level = 1; level <= max_level; level++) {
>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>> +	for (level = 1; level <= usable_level; level++) {
>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>  
>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>  				     pristate, sprstate, curstate, wm);
>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>  		 * register maximums since such watermarks are
>>  		 * always invalid.
>>  		 */
>> -		if (level > usable_level)
>> -			continue;
>> -
>> -		if (ilk_validate_wm_level(level, &max, wm))
>> -			pipe_wm->wm[level] = *wm;
>> -		else
>> -			usable_level = level;
>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>> +			memset(wm, 0, sizeof(*wm));
>> +			break;
>> +		}
>>  	}
>>  
>>  	return 0;
> 
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index a19ec06..3ce9ba3 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>  
>>  struct intel_pipe_wm {
>>  	struct intel_wm_level wm[5];
>> -	struct intel_wm_level raw_wm[5];
>>  	uint32_t linetime;
>>  	bool fbc_wm_enabled;
>>  	bool pipe_enabled;
> 
> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
> 4.9.62.
> 
> I've cc:ed the authors of that patch now.
> 
> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
> a follow-on patch that resolved this issue in mainline?
> 
> thanks,
> 
> greg k-h
> 

OK, after reverting the patches, the flicker *is* gone.

BTW (for the future): Was it the right way to address
stable@vger.kernel.org in this matter or would the bugreport at
freedesktop.org have been enough? I'm a bit unsure about that.

Thanks.
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
> Greg KH wrote:
> > On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
> >> Greg KH wrote:
> >>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> >>>> Greg KH wrote:
> >>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> >>>>>> Hi!
> >>>>>>
> >>>>>> Hopefully the right addressee.
> >>>>>>
> >>>>>> Encountered two bad backports which cause screen-flicker.
> >>>>>> dmesg shows:
> >>>>>>
> >>>>>> ...
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> >>>>>> ...
> >>>>>>
> >>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
> >>>>>>
> >>>>>> The backports are:
> >>>>>>
> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> >>>>>> b/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>     index 49de476..277a802 100644
> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >>>>>> b/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>     index a19ec06..3ce9ba3 100644
> >>>>>>
> >>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
> >>>>>> else OK so far.
> >>>>>
> >>>>> So which commit was the one that caused the problem?  I will be glad to
> >>>>> revert it.
> >>>>>
> >>>>> thanks,
> >>>>>
> >>>>> greg k-h
> >>>>>
> >>>>>
> >>>>
> >>>> I started by reverting the more complex one first ("index
> >>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> >>>
> >>> What git commit id is that?  I don't see those ids in the 4.9-stable
> >>> tree.
> >>>
> >>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> >>>> kernel compiled just fine and the problems were gone (still are).
> >>>
> >>> Same here, what git commit id was this?
> >>>
> >>> thanks,
> >>>
> >>> greg k-h
> >>>
> >>
> >> OK, no mistake. IIRC, I took the patches (and the IDs) from the
> >> changelog for patch-4.9.62. I've attached both, so you can check yourself.
> >>
> >> I've also applied a freshly downloaded patch-4.9.62 to a freshly
> >> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
> >> reverted the two patches but I'm confident that after having done so the
> >> flicker will be gone. If not I'll let you know.
> >>
> >> As a good news: 4.14 is *not* affected. So to me it seems those two
> >> patches are part of sort of a package and can not be backported alone.
> >>
> >> So long!
> >> Rainer Fiebig
> > 
> >> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >> index 49de476..277a802 100644
> >> --- a/drivers/gpu/drm/i915/intel_pm.c
> >> +++ b/drivers/gpu/drm/i915/intel_pm.c
> >> @@ -27,6 +27,7 @@
> >>  
> >>  #include <linux/cpufreq.h>
> >>  #include <drm/drm_plane_helper.h>
> >> +#include <drm/drm_atomic_helper.h>
> >>  #include "i915_drv.h"
> >>  #include "intel_drv.h"
> >>  #include "../../../platform/x86/intel_ips.h"
> >> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
> >>  				 const struct intel_crtc *intel_crtc,
> >>  				 int level,
> >>  				 struct intel_crtc_state *cstate,
> >> -				 struct intel_plane_state *pristate,
> >> -				 struct intel_plane_state *sprstate,
> >> -				 struct intel_plane_state *curstate,
> >> +				 const struct intel_plane_state *pristate,
> >> +				 const struct intel_plane_state *sprstate,
> >> +				 const struct intel_plane_state *curstate,
> >>  				 struct intel_wm_level *result)
> >>  {
> >>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> >> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>  	struct intel_pipe_wm *pipe_wm;
> >>  	struct drm_device *dev = state->dev;
> >>  	const struct drm_i915_private *dev_priv = to_i915(dev);
> >> -	struct intel_plane *intel_plane;
> >> -	struct intel_plane_state *pristate = NULL;
> >> -	struct intel_plane_state *sprstate = NULL;
> >> -	struct intel_plane_state *curstate = NULL;
> >> +	struct drm_plane *plane;
> >> +	const struct drm_plane_state *plane_state;
> >> +	const struct intel_plane_state *pristate = NULL;
> >> +	const struct intel_plane_state *sprstate = NULL;
> >> +	const struct intel_plane_state *curstate = NULL;
> >>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
> >>  	struct ilk_wm_maximums max;
> >>  
> >>  	pipe_wm = &cstate->wm.ilk.optimal;
> >>  
> >> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> >> -		struct intel_plane_state *ps;
> >> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> >> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
> >>  
> >> -		ps = intel_atomic_get_existing_plane_state(state,
> >> -							   intel_plane);
> >> -		if (!ps)
> >> -			continue;
> >> -
> >> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> >> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> >>  			pristate = ps;
> >> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> >> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> >>  			sprstate = ps;
> >> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> >> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
> >>  			curstate = ps;
> >>  	}
> >>  
> >> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>  	if (pipe_wm->sprites_scaled)
> >>  		usable_level = 0;
> >>  
> >> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> >> -
> >>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> >> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> >> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
> >>  
> >>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> >>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> >> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>  
> >>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
> >>  
> >> -	for (level = 1; level <= max_level; level++) {
> >> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> >> +	for (level = 1; level <= usable_level; level++) {
> >> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
> >>  
> >>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
> >>  				     pristate, sprstate, curstate, wm);
> >> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>  		 * register maximums since such watermarks are
> >>  		 * always invalid.
> >>  		 */
> >> -		if (level > usable_level)
> >> -			continue;
> >> -
> >> -		if (ilk_validate_wm_level(level, &max, wm))
> >> -			pipe_wm->wm[level] = *wm;
> >> -		else
> >> -			usable_level = level;
> >> +		if (!ilk_validate_wm_level(level, &max, wm)) {
> >> +			memset(wm, 0, sizeof(*wm));
> >> +			break;
> >> +		}
> >>  	}
> >>  
> >>  	return 0;
> > 
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index a19ec06..3ce9ba3 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
> >>  
> >>  struct intel_pipe_wm {
> >>  	struct intel_wm_level wm[5];
> >> -	struct intel_wm_level raw_wm[5];
> >>  	uint32_t linetime;
> >>  	bool fbc_wm_enabled;
> >>  	bool pipe_enabled;
> > 
> > Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
> > upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
> > 4.9.62.
> > 
> > I've cc:ed the authors of that patch now.
> > 
> > Maarten, any hints?  Should I revert this from 4.9-stable, or was there
> > a follow-on patch that resolved this issue in mainline?
> > 
> > thanks,
> > 
> > greg k-h
> > 
> 
> OK, after reverting the patches, the flicker *is* gone.

Thanks for confirming this.

> BTW (for the future): Was it the right way to address
> stable@vger.kernel.org in this matter or would the bugreport at
> freedesktop.org have been enough? I'm a bit unsure about that.

I have no idea what the i915 developers want, but as far as I'm
concerned, sending this to stable@vger was fine with me, I have no
problem doing a bit of work in tracking down the specific patch before
bugging the developers involved.

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Jani Nikula]

On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>> Greg KH wrote:
>> > On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>> >> Greg KH wrote:
>> >>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>> >>>> Greg KH wrote:
>> >>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>> >>>>>> Hi!
>> >>>>>>
>> >>>>>> Hopefully the right addressee.
>> >>>>>>
>> >>>>>> Encountered two bad backports which cause screen-flicker.
>> >>>>>> dmesg shows:
>> >>>>>>
>> >>>>>> ...
>> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>> >>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>> >>>>>> ...
>> >>>>>>
>> >>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>> >>>>>>
>> >>>>>> The backports are:
>> >>>>>>
>> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>> >>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>> >>>>>>     index 49de476..277a802 100644
>> >>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> >>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>> >>>>>>     index a19ec06..3ce9ba3 100644
>> >>>>>>
>> >>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>> >>>>>> else OK so far.
>> >>>>>
>> >>>>> So which commit was the one that caused the problem?  I will be glad to
>> >>>>> revert it.
>> >>>>>
>> >>>>> thanks,
>> >>>>>
>> >>>>> greg k-h
>> >>>>>
>> >>>>>
>> >>>>
>> >>>> I started by reverting the more complex one first ("index
>> >>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>> >>>
>> >>> What git commit id is that?  I don't see those ids in the 4.9-stable
>> >>> tree.
>> >>>
>> >>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>> >>>> kernel compiled just fine and the problems were gone (still are).
>> >>>
>> >>> Same here, what git commit id was this?
>> >>>
>> >>> thanks,
>> >>>
>> >>> greg k-h
>> >>>
>> >>
>> >> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>> >> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>> >>
>> >> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>> >> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>> >> reverted the two patches but I'm confident that after having done so the
>> >> flicker will be gone. If not I'll let you know.
>> >>
>> >> As a good news: 4.14 is *not* affected. So to me it seems those two
>> >> patches are part of sort of a package and can not be backported alone.
>> >>
>> >> So long!
>> >> Rainer Fiebig
>> > 
>> >> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> >> index 49de476..277a802 100644
>> >> --- a/drivers/gpu/drm/i915/intel_pm.c
>> >> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> >> @@ -27,6 +27,7 @@
>> >>  
>> >>  #include <linux/cpufreq.h>
>> >>  #include <drm/drm_plane_helper.h>
>> >> +#include <drm/drm_atomic_helper.h>
>> >>  #include "i915_drv.h"
>> >>  #include "intel_drv.h"
>> >>  #include "../../../platform/x86/intel_ips.h"
>> >> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>> >>  				 const struct intel_crtc *intel_crtc,
>> >>  				 int level,
>> >>  				 struct intel_crtc_state *cstate,
>> >> -				 struct intel_plane_state *pristate,
>> >> -				 struct intel_plane_state *sprstate,
>> >> -				 struct intel_plane_state *curstate,
>> >> +				 const struct intel_plane_state *pristate,
>> >> +				 const struct intel_plane_state *sprstate,
>> >> +				 const struct intel_plane_state *curstate,
>> >>  				 struct intel_wm_level *result)
>> >>  {
>> >>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>> >> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>> >>  	struct intel_pipe_wm *pipe_wm;
>> >>  	struct drm_device *dev = state->dev;
>> >>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>> >> -	struct intel_plane *intel_plane;
>> >> -	struct intel_plane_state *pristate = NULL;
>> >> -	struct intel_plane_state *sprstate = NULL;
>> >> -	struct intel_plane_state *curstate = NULL;
>> >> +	struct drm_plane *plane;
>> >> +	const struct drm_plane_state *plane_state;
>> >> +	const struct intel_plane_state *pristate = NULL;
>> >> +	const struct intel_plane_state *sprstate = NULL;
>> >> +	const struct intel_plane_state *curstate = NULL;
>> >>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>> >>  	struct ilk_wm_maximums max;
>> >>  
>> >>  	pipe_wm = &cstate->wm.ilk.optimal;
>> >>  
>> >> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>> >> -		struct intel_plane_state *ps;
>> >> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>> >> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>> >>  
>> >> -		ps = intel_atomic_get_existing_plane_state(state,
>> >> -							   intel_plane);
>> >> -		if (!ps)
>> >> -			continue;
>> >> -
>> >> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>> >> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>> >>  			pristate = ps;
>> >> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>> >> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>> >>  			sprstate = ps;
>> >> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>> >> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>> >>  			curstate = ps;
>> >>  	}
>> >>  
>> >> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>> >>  	if (pipe_wm->sprites_scaled)
>> >>  		usable_level = 0;
>> >>  
>> >> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>> >> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>> >> -
>> >>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>> >> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>> >> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>> >> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>> >>  
>> >>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>> >>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>> >> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>> >>  
>> >>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>> >>  
>> >> -	for (level = 1; level <= max_level; level++) {
>> >> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>> >> +	for (level = 1; level <= usable_level; level++) {
>> >> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>> >>  
>> >>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>> >>  				     pristate, sprstate, curstate, wm);
>> >> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>> >>  		 * register maximums since such watermarks are
>> >>  		 * always invalid.
>> >>  		 */
>> >> -		if (level > usable_level)
>> >> -			continue;
>> >> -
>> >> -		if (ilk_validate_wm_level(level, &max, wm))
>> >> -			pipe_wm->wm[level] = *wm;
>> >> -		else
>> >> -			usable_level = level;
>> >> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>> >> +			memset(wm, 0, sizeof(*wm));
>> >> +			break;
>> >> +		}
>> >>  	}
>> >>  
>> >>  	return 0;
>> > 
>> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> >> index a19ec06..3ce9ba3 100644
>> >> --- a/drivers/gpu/drm/i915/intel_drv.h
>> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> >> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>> >>  
>> >>  struct intel_pipe_wm {
>> >>  	struct intel_wm_level wm[5];
>> >> -	struct intel_wm_level raw_wm[5];
>> >>  	uint32_t linetime;
>> >>  	bool fbc_wm_enabled;
>> >>  	bool pipe_enabled;
>> > 
>> > Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>> > upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>> > 4.9.62.
>> > 
>> > I've cc:ed the authors of that patch now.
>> > 
>> > Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>> > a follow-on patch that resolved this issue in mainline?
>> > 
>> > thanks,
>> > 
>> > greg k-h
>> > 
>> 
>> OK, after reverting the patches, the flicker *is* gone.
>
> Thanks for confirming this.
>
>> BTW (for the future): Was it the right way to address
>> stable@vger.kernel.org in this matter or would the bugreport at
>> freedesktop.org have been enough? I'm a bit unsure about that.
>
> I have no idea what the i915 developers want, but as far as I'm
> concerned, sending this to stable@vger was fine with me, I have no
> problem doing a bit of work in tracking down the specific patch before
> bugging the developers involved.

Well, this one we wanted to be backported, and so indicated with cc:
stable, but apparently it went south anyway. :(

Rainer, does v4.14 work for you? I.e. is the commit okay or not before
the backport?

Maarten?

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Technology Center

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Jani Nikula wrote:
> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>> Greg KH wrote:
>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>> Greg KH wrote:
>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>> Greg KH wrote:
>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>> Hi!
>>>>>>>>>
>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>
>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>> dmesg shows:
>>>>>>>>>
>>>>>>>>> ...
>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>> ...
>>>>>>>>>
>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>
>>>>>>>>> The backports are:
>>>>>>>>>
>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>
>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>> else OK so far.
>>>>>>>>
>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>> revert it.
>>>>>>>>
>>>>>>>> thanks,
>>>>>>>>
>>>>>>>> greg k-h
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> I started by reverting the more complex one first ("index
>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>
>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>> tree.
>>>>>>
>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>
>>>>>> Same here, what git commit id was this?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> greg k-h
>>>>>>
>>>>>
>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>
>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>> reverted the two patches but I'm confident that after having done so the
>>>>> flicker will be gone. If not I'll let you know.
>>>>>
>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>
>>>>> So long!
>>>>> Rainer Fiebig
>>>>
>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>> index 49de476..277a802 100644
>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>> @@ -27,6 +27,7 @@
>>>>>  
>>>>>  #include <linux/cpufreq.h>
>>>>>  #include <drm/drm_plane_helper.h>
>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>  #include "i915_drv.h"
>>>>>  #include "intel_drv.h"
>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>  				 int level,
>>>>>  				 struct intel_crtc_state *cstate,
>>>>> -				 struct intel_plane_state *pristate,
>>>>> -				 struct intel_plane_state *sprstate,
>>>>> -				 struct intel_plane_state *curstate,
>>>>> +				 const struct intel_plane_state *pristate,
>>>>> +				 const struct intel_plane_state *sprstate,
>>>>> +				 const struct intel_plane_state *curstate,
>>>>>  				 struct intel_wm_level *result)
>>>>>  {
>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>  	struct drm_device *dev = state->dev;
>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>> -	struct intel_plane *intel_plane;
>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>> +	struct drm_plane *plane;
>>>>> +	const struct drm_plane_state *plane_state;
>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>  	struct ilk_wm_maximums max;
>>>>>  
>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>  
>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>> -		struct intel_plane_state *ps;
>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>  
>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>> -							   intel_plane);
>>>>> -		if (!ps)
>>>>> -			continue;
>>>>> -
>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>  			pristate = ps;
>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>  			sprstate = ps;
>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>  			curstate = ps;
>>>>>  	}
>>>>>  
>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>  		usable_level = 0;
>>>>>  
>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>> -
>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>  
>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>  
>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>  
>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>  
>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>  				     pristate, sprstate, curstate, wm);
>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>  		 * register maximums since such watermarks are
>>>>>  		 * always invalid.
>>>>>  		 */
>>>>> -		if (level > usable_level)
>>>>> -			continue;
>>>>> -
>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>> -			pipe_wm->wm[level] = *wm;
>>>>> -		else
>>>>> -			usable_level = level;
>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>> +			break;
>>>>> +		}
>>>>>  	}
>>>>>  
>>>>>  	return 0;
>>>>
>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>> index a19ec06..3ce9ba3 100644
>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>  
>>>>>  struct intel_pipe_wm {
>>>>>  	struct intel_wm_level wm[5];
>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>  	uint32_t linetime;
>>>>>  	bool fbc_wm_enabled;
>>>>>  	bool pipe_enabled;
>>>>
>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>> 4.9.62.
>>>>
>>>> I've cc:ed the authors of that patch now.
>>>>
>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>> a follow-on patch that resolved this issue in mainline?
>>>>
>>>> thanks,
>>>>
>>>> greg k-h
>>>>
>>>
>>> OK, after reverting the patches, the flicker *is* gone.
>>
>> Thanks for confirming this.
>>
>>> BTW (for the future): Was it the right way to address
>>> stable@vger.kernel.org in this matter or would the bugreport at
>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>
>> I have no idea what the i915 developers want, but as far as I'm
>> concerned, sending this to stable@vger was fine with me, I have no
>> problem doing a bit of work in tracking down the specific patch before
>> bugging the developers involved.
> 
> Well, this one we wanted to be backported, and so indicated with cc:
> stable, but apparently it went south anyway. :(
> 
> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
> the backport?
> 
> Maarten?
> 
> BR,
> Jani.
> 
> 

4.14 is OK, no problems.

So long!
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Maarten Lankhorst]

Op 20-11-17 om 09:51 schreef Rainer Fiebig:
> Jani Nikula wrote:
>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>> Greg KH wrote:
>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>> Greg KH wrote:
>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>> Greg KH wrote:
>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>> Hi!
>>>>>>>>>>
>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>
>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>> dmesg shows:
>>>>>>>>>>
>>>>>>>>>> ...
>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>> ...
>>>>>>>>>>
>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>
>>>>>>>>>> The backports are:
>>>>>>>>>>
>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>
>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>> else OK so far.
>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>> revert it.
>>>>>>>>>
>>>>>>>>> thanks,
>>>>>>>>>
>>>>>>>>> greg k-h
>>>>>>>>>
>>>>>>>>>
>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>> tree.
>>>>>>>
>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>> Same here, what git commit id was this?
>>>>>>>
>>>>>>> thanks,
>>>>>>>
>>>>>>> greg k-h
>>>>>>>
>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>
>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>
>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>
>>>>>> So long!
>>>>>> Rainer Fiebig
>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>> index 49de476..277a802 100644
>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>> @@ -27,6 +27,7 @@
>>>>>>  
>>>>>>  #include <linux/cpufreq.h>
>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>  #include "i915_drv.h"
>>>>>>  #include "intel_drv.h"
>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>  				 int level,
>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>> -				 struct intel_plane_state *pristate,
>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>> -				 struct intel_plane_state *curstate,
>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>  				 struct intel_wm_level *result)
>>>>>>  {
>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>> -	struct intel_plane *intel_plane;
>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>> +	struct drm_plane *plane;
>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>  	struct ilk_wm_maximums max;
>>>>>>  
>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>  
>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>> -		struct intel_plane_state *ps;
>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>  
>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>> -							   intel_plane);
>>>>>> -		if (!ps)
>>>>>> -			continue;
>>>>>> -
>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>  			pristate = ps;
>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>  			sprstate = ps;
>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>  			curstate = ps;
>>>>>>  	}
>>>>>>  
>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>  		usable_level = 0;
>>>>>>  
>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>> -
>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>  
>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>  
>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>  
>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>  
>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>  		 * register maximums since such watermarks are
>>>>>>  		 * always invalid.
>>>>>>  		 */
>>>>>> -		if (level > usable_level)
>>>>>> -			continue;
>>>>>> -
>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>> -		else
>>>>>> -			usable_level = level;
>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>> +			break;
>>>>>> +		}
>>>>>>  	}
>>>>>>  
>>>>>>  	return 0;
>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>> index a19ec06..3ce9ba3 100644
>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>  
>>>>>>  struct intel_pipe_wm {
>>>>>>  	struct intel_wm_level wm[5];
>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>  	uint32_t linetime;
>>>>>>  	bool fbc_wm_enabled;
>>>>>>  	bool pipe_enabled;
>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>> 4.9.62.
>>>>>
>>>>> I've cc:ed the authors of that patch now.
>>>>>
>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>
>>>>> thanks,
>>>>>
>>>>> greg k-h
>>>>>
>>>> OK, after reverting the patches, the flicker *is* gone.
>>> Thanks for confirming this.
>>>
>>>> BTW (for the future): Was it the right way to address
>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>> I have no idea what the i915 developers want, but as far as I'm
>>> concerned, sending this to stable@vger was fine with me, I have no
>>> problem doing a bit of work in tracking down the specific patch before
>>> bugging the developers involved.
>> Well, this one we wanted to be backported, and so indicated with cc:
>> stable, but apparently it went south anyway. :(
>>
>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>> the backport?
>>
>> Maarten?
>>
>> BR,
>> Jani.
>>
>>
> 4.14 is OK, no problems.
>
> So long!
> Rainer Fiebig

What happens when you apply both other backported patches on top?

https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Maarten Lankhorst wrote:
> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>> Jani Nikula wrote:
>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>> Greg KH wrote:
>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>> Greg KH wrote:
>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>> Greg KH wrote:
>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>> Hi!
>>>>>>>>>>>
>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>
>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>
>>>>>>>>>>> ...
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>> ...
>>>>>>>>>>>
>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>
>>>>>>>>>>> The backports are:
>>>>>>>>>>>
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>
>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>> else OK so far.
>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>> revert it.
>>>>>>>>>>
>>>>>>>>>> thanks,
>>>>>>>>>>
>>>>>>>>>> greg k-h
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>> tree.
>>>>>>>>
>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>> Same here, what git commit id was this?
>>>>>>>>
>>>>>>>> thanks,
>>>>>>>>
>>>>>>>> greg k-h
>>>>>>>>
>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>
>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>
>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>
>>>>>>> So long!
>>>>>>> Rainer Fiebig
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> index 49de476..277a802 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>  
>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>  #include "i915_drv.h"
>>>>>>>  #include "intel_drv.h"
>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>  				 int level,
>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>  {
>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>> +	struct drm_plane *plane;
>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>  
>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>  
>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>> -		struct intel_plane_state *ps;
>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>  
>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>> -							   intel_plane);
>>>>>>> -		if (!ps)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>  			pristate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>  			sprstate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>  			curstate = ps;
>>>>>>>  	}
>>>>>>>  
>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>  		usable_level = 0;
>>>>>>>  
>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>> -
>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>  
>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  
>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>  
>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>  
>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>  		 * always invalid.
>>>>>>>  		 */
>>>>>>> -		if (level > usable_level)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>> -		else
>>>>>>> -			usable_level = level;
>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>> +			break;
>>>>>>> +		}
>>>>>>>  	}
>>>>>>>  
>>>>>>>  	return 0;
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>  
>>>>>>>  struct intel_pipe_wm {
>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>  	uint32_t linetime;
>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>  	bool pipe_enabled;
>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>> 4.9.62.
>>>>>>
>>>>>> I've cc:ed the authors of that patch now.
>>>>>>
>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> greg k-h
>>>>>>
>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>> Thanks for confirming this.
>>>>
>>>>> BTW (for the future): Was it the right way to address
>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>> I have no idea what the i915 developers want, but as far as I'm
>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>> problem doing a bit of work in tracking down the specific patch before
>>>> bugging the developers involved.
>>> Well, this one we wanted to be backported, and so indicated with cc:
>>> stable, but apparently it went south anyway. :(
>>>
>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>> the backport?
>>>
>>> Maarten?
>>>
>>> BR,
>>> Jani.
>>>
>>>
>> 4.14 is OK, no problems.
>>
>> So long!
>> Rainer Fiebig
> 
> What happens when you apply both other backported patches on top?
> 
> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> 

On top of 4.14?

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Maarten Lankhorst]

Op 20-11-17 om 12:38 schreef Rainer Fiebig:
> Maarten Lankhorst wrote:
>> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>>> Jani Nikula wrote:
>>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>>> Greg KH wrote:
>>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>>> Greg KH wrote:
>>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>> Hi!
>>>>>>>>>>>>
>>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>>
>>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>>
>>>>>>>>>>>> ...
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>>> ...
>>>>>>>>>>>>
>>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>>
>>>>>>>>>>>> The backports are:
>>>>>>>>>>>>
>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>>
>>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>>> else OK so far.
>>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>>> revert it.
>>>>>>>>>>>
>>>>>>>>>>> thanks,
>>>>>>>>>>>
>>>>>>>>>>> greg k-h
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>>> tree.
>>>>>>>>>
>>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>>> Same here, what git commit id was this?
>>>>>>>>>
>>>>>>>>> thanks,
>>>>>>>>>
>>>>>>>>> greg k-h
>>>>>>>>>
>>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>>
>>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>>
>>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>>
>>>>>>>> So long!
>>>>>>>> Rainer Fiebig
>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> index 49de476..277a802 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>>  
>>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>>  #include "i915_drv.h"
>>>>>>>>  #include "intel_drv.h"
>>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>>  				 int level,
>>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>>  {
>>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>>> +	struct drm_plane *plane;
>>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>>  
>>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>>  
>>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>>> -		struct intel_plane_state *ps;
>>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>>  
>>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>>> -							   intel_plane);
>>>>>>>> -		if (!ps)
>>>>>>>> -			continue;
>>>>>>>> -
>>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>  			pristate = ps;
>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>  			sprstate = ps;
>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>  			curstate = ps;
>>>>>>>>  	}
>>>>>>>>  
>>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>>  		usable_level = 0;
>>>>>>>>  
>>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>>> -
>>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>>  
>>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  
>>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>>  
>>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>>  
>>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>>  		 * always invalid.
>>>>>>>>  		 */
>>>>>>>> -		if (level > usable_level)
>>>>>>>> -			continue;
>>>>>>>> -
>>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>>> -		else
>>>>>>>> -			usable_level = level;
>>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>>> +			break;
>>>>>>>> +		}
>>>>>>>>  	}
>>>>>>>>  
>>>>>>>>  	return 0;
>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>>  
>>>>>>>>  struct intel_pipe_wm {
>>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>>  	uint32_t linetime;
>>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>>  	bool pipe_enabled;
>>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>>> 4.9.62.
>>>>>>>
>>>>>>> I've cc:ed the authors of that patch now.
>>>>>>>
>>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>>
>>>>>>> thanks,
>>>>>>>
>>>>>>> greg k-h
>>>>>>>
>>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>>> Thanks for confirming this.
>>>>>
>>>>>> BTW (for the future): Was it the right way to address
>>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>>> I have no idea what the i915 developers want, but as far as I'm
>>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>>> problem doing a bit of work in tracking down the specific patch before
>>>>> bugging the developers involved.
>>>> Well, this one we wanted to be backported, and so indicated with cc:
>>>> stable, but apparently it went south anyway. :(
>>>>
>>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>>> the backport?
>>>>
>>>> Maarten?
>>>>
>>>> BR,
>>>> Jani.
>>>>
>>>>
>>> 4.14 is OK, no problems.
>>>
>>> So long!
>>> Rainer Fiebig
>> What happens when you apply both other backported patches on top?
>>
>> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
>>
> On top of 4.14?

No, on top of v4.9 :-)

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Maarten Lankhorst wrote:
> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>> Jani Nikula wrote:
>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>> Greg KH wrote:
>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>> Greg KH wrote:
>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>> Greg KH wrote:
>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>> Hi!
>>>>>>>>>>>
>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>
>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>
>>>>>>>>>>> ...
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>> ...
>>>>>>>>>>>
>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>
>>>>>>>>>>> The backports are:
>>>>>>>>>>>
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>
>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>> else OK so far.
>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>> revert it.
>>>>>>>>>>
>>>>>>>>>> thanks,
>>>>>>>>>>
>>>>>>>>>> greg k-h
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>> tree.
>>>>>>>>
>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>> Same here, what git commit id was this?
>>>>>>>>
>>>>>>>> thanks,
>>>>>>>>
>>>>>>>> greg k-h
>>>>>>>>
>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>
>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>
>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>
>>>>>>> So long!
>>>>>>> Rainer Fiebig
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> index 49de476..277a802 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>  
>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>  #include "i915_drv.h"
>>>>>>>  #include "intel_drv.h"
>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>  				 int level,
>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>  {
>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>> +	struct drm_plane *plane;
>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>  
>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>  
>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>> -		struct intel_plane_state *ps;
>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>  
>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>> -							   intel_plane);
>>>>>>> -		if (!ps)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>  			pristate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>  			sprstate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>  			curstate = ps;
>>>>>>>  	}
>>>>>>>  
>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>  		usable_level = 0;
>>>>>>>  
>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>> -
>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>  
>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  
>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>  
>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>  
>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>  		 * always invalid.
>>>>>>>  		 */
>>>>>>> -		if (level > usable_level)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>> -		else
>>>>>>> -			usable_level = level;
>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>> +			break;
>>>>>>> +		}
>>>>>>>  	}
>>>>>>>  
>>>>>>>  	return 0;
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>  
>>>>>>>  struct intel_pipe_wm {
>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>  	uint32_t linetime;
>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>  	bool pipe_enabled;
>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>> 4.9.62.
>>>>>>
>>>>>> I've cc:ed the authors of that patch now.
>>>>>>
>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> greg k-h
>>>>>>
>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>> Thanks for confirming this.
>>>>
>>>>> BTW (for the future): Was it the right way to address
>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>> I have no idea what the i915 developers want, but as far as I'm
>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>> problem doing a bit of work in tracking down the specific patch before
>>>> bugging the developers involved.
>>> Well, this one we wanted to be backported, and so indicated with cc:
>>> stable, but apparently it went south anyway. :(
>>>
>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>> the backport?
>>>
>>> Maarten?
>>>
>>> BR,
>>> Jani.
>>>
>>>
>> 4.14 is OK, no problems.
>>
>> So long!
>> Rainer Fiebig
> 
> What happens when you apply both other backported patches on top?
> 
> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> 

Ah, you probably mean applying the latest two patches in your repo on
top of the two orig-backports for 4.9.62?

I'll try.

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Maarten Lankhorst wrote:
> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>> Jani Nikula wrote:
>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>> Greg KH wrote:
>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>> Greg KH wrote:
>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>> Greg KH wrote:
>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>> Hi!
>>>>>>>>>>>
>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>
>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>
>>>>>>>>>>> ...
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>> ...
>>>>>>>>>>>
>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>
>>>>>>>>>>> The backports are:
>>>>>>>>>>>
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>
>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>> else OK so far.
>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>> revert it.
>>>>>>>>>>
>>>>>>>>>> thanks,
>>>>>>>>>>
>>>>>>>>>> greg k-h
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>> tree.
>>>>>>>>
>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>> Same here, what git commit id was this?
>>>>>>>>
>>>>>>>> thanks,
>>>>>>>>
>>>>>>>> greg k-h
>>>>>>>>
>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>
>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>
>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>
>>>>>>> So long!
>>>>>>> Rainer Fiebig
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> index 49de476..277a802 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>  
>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>  #include "i915_drv.h"
>>>>>>>  #include "intel_drv.h"
>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>  				 int level,
>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>  {
>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>> +	struct drm_plane *plane;
>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>  
>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>  
>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>> -		struct intel_plane_state *ps;
>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>  
>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>> -							   intel_plane);
>>>>>>> -		if (!ps)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>  			pristate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>  			sprstate = ps;
>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>  			curstate = ps;
>>>>>>>  	}
>>>>>>>  
>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>  		usable_level = 0;
>>>>>>>  
>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>> -
>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>  
>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  
>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>  
>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>  
>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>  		 * always invalid.
>>>>>>>  		 */
>>>>>>> -		if (level > usable_level)
>>>>>>> -			continue;
>>>>>>> -
>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>> -		else
>>>>>>> -			usable_level = level;
>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>> +			break;
>>>>>>> +		}
>>>>>>>  	}
>>>>>>>  
>>>>>>>  	return 0;
>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>  
>>>>>>>  struct intel_pipe_wm {
>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>  	uint32_t linetime;
>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>  	bool pipe_enabled;
>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>> 4.9.62.
>>>>>>
>>>>>> I've cc:ed the authors of that patch now.
>>>>>>
>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> greg k-h
>>>>>>
>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>> Thanks for confirming this.
>>>>
>>>>> BTW (for the future): Was it the right way to address
>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>> I have no idea what the i915 developers want, but as far as I'm
>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>> problem doing a bit of work in tracking down the specific patch before
>>>> bugging the developers involved.
>>> Well, this one we wanted to be backported, and so indicated with cc:
>>> stable, but apparently it went south anyway. :(
>>>
>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>> the backport?
>>>
>>> Maarten?
>>>
>>> BR,
>>> Jani.
>>>
>>>
>> 4.14 is OK, no problems.
>>
>> So long!
>> Rainer Fiebig
> 
> What happens when you apply both other backported patches on top?
> 
> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> 

So I applied the 2 new patches on top of the orig. 4.9.62.

Better now but not yet completely OK:

...
[drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
[drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
...

No random flicker so far but flicker when I enter a character in an
x-terminal.

Seems your patches fixed only half of the pipes. ;)

So long!
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Rainer Fiebig wrote:
> Maarten Lankhorst wrote:
>> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>>> Jani Nikula wrote:
>>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>>> Greg KH wrote:
>>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>>> Greg KH wrote:
>>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>> Hi!
>>>>>>>>>>>>
>>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>>
>>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>>
>>>>>>>>>>>> ...
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>>> ...
>>>>>>>>>>>>
>>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>>
>>>>>>>>>>>> The backports are:
>>>>>>>>>>>>
>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>>
>>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>>> else OK so far.
>>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>>> revert it.
>>>>>>>>>>>
>>>>>>>>>>> thanks,
>>>>>>>>>>>
>>>>>>>>>>> greg k-h
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>>> tree.
>>>>>>>>>
>>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>>> Same here, what git commit id was this?
>>>>>>>>>
>>>>>>>>> thanks,
>>>>>>>>>
>>>>>>>>> greg k-h
>>>>>>>>>
>>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>>
>>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>>
>>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>>
>>>>>>>> So long!
>>>>>>>> Rainer Fiebig
>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> index 49de476..277a802 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>>  
>>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>>  #include "i915_drv.h"
>>>>>>>>  #include "intel_drv.h"
>>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>>  				 int level,
>>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>>  {
>>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>>> +	struct drm_plane *plane;
>>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>>  
>>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>>  
>>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>>> -		struct intel_plane_state *ps;
>>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>>  
>>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>>> -							   intel_plane);
>>>>>>>> -		if (!ps)
>>>>>>>> -			continue;
>>>>>>>> -
>>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>  			pristate = ps;
>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>  			sprstate = ps;
>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>  			curstate = ps;
>>>>>>>>  	}
>>>>>>>>  
>>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>>  		usable_level = 0;
>>>>>>>>  
>>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>>> -
>>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>>  
>>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  
>>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>>  
>>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>>  
>>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>>  		 * always invalid.
>>>>>>>>  		 */
>>>>>>>> -		if (level > usable_level)
>>>>>>>> -			continue;
>>>>>>>> -
>>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>>> -		else
>>>>>>>> -			usable_level = level;
>>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>>> +			break;
>>>>>>>> +		}
>>>>>>>>  	}
>>>>>>>>  
>>>>>>>>  	return 0;
>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>>  
>>>>>>>>  struct intel_pipe_wm {
>>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>>  	uint32_t linetime;
>>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>>  	bool pipe_enabled;
>>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>>> 4.9.62.
>>>>>>>
>>>>>>> I've cc:ed the authors of that patch now.
>>>>>>>
>>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>>
>>>>>>> thanks,
>>>>>>>
>>>>>>> greg k-h
>>>>>>>
>>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>>> Thanks for confirming this.
>>>>>
>>>>>> BTW (for the future): Was it the right way to address
>>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>>> I have no idea what the i915 developers want, but as far as I'm
>>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>>> problem doing a bit of work in tracking down the specific patch before
>>>>> bugging the developers involved.
>>>> Well, this one we wanted to be backported, and so indicated with cc:
>>>> stable, but apparently it went south anyway. :(
>>>>
>>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>>> the backport?
>>>>
>>>> Maarten?
>>>>
>>>> BR,
>>>> Jani.
>>>>
>>>>
>>> 4.14 is OK, no problems.
>>>
>>> So long!
>>> Rainer Fiebig
>>
>> What happens when you apply both other backported patches on top?
>>
>> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
>>
> 
> So I applied the 2 new patches on top of the orig. 4.9.62.
> 
> Better now but not yet completely OK:
> 
> ...
> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> ...
> 
> No random flicker so far but flicker when I enter a character in an
> x-terminal.
> 
> Seems your patches fixed only half of the pipes. ;)
> 
> So long!
> Rainer Fiebig
> 

There's also random flicker after a while.

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Thu, Nov 23, 2017 at 10:09:25PM +0100, Rainer Fiebig wrote:
> Rainer Fiebig wrote:
> > Maarten Lankhorst wrote:
> >> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
> >>> Jani Nikula wrote:
> >>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
> >>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
> >>>>>> Greg KH wrote:
> >>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
> >>>>>>>> Greg KH wrote:
> >>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> >>>>>>>>>> Greg KH wrote:
> >>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> >>>>>>>>>>>> Hi!
> >>>>>>>>>>>>
> >>>>>>>>>>>> Hopefully the right addressee.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
> >>>>>>>>>>>> dmesg shows:
> >>>>>>>>>>>>
> >>>>>>>>>>>> ...
> >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> >>>>>>>>>>>> ...
> >>>>>>>>>>>>
> >>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
> >>>>>>>>>>>>
> >>>>>>>>>>>> The backports are:
> >>>>>>>>>>>>
> >>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>>>>>>>     index 49de476..277a802 100644
> >>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
> >>>>>>>>>>>>
> >>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
> >>>>>>>>>>>> else OK so far.
> >>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
> >>>>>>>>>>> revert it.
> >>>>>>>>>>>
> >>>>>>>>>>> thanks,
> >>>>>>>>>>>
> >>>>>>>>>>> greg k-h
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>> I started by reverting the more complex one first ("index
> >>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> >>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
> >>>>>>>>> tree.
> >>>>>>>>>
> >>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> >>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
> >>>>>>>>> Same here, what git commit id was this?
> >>>>>>>>>
> >>>>>>>>> thanks,
> >>>>>>>>>
> >>>>>>>>> greg k-h
> >>>>>>>>>
> >>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
> >>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
> >>>>>>>>
> >>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
> >>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
> >>>>>>>> reverted the two patches but I'm confident that after having done so the
> >>>>>>>> flicker will be gone. If not I'll let you know.
> >>>>>>>>
> >>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
> >>>>>>>> patches are part of sort of a package and can not be backported alone.
> >>>>>>>>
> >>>>>>>> So long!
> >>>>>>>> Rainer Fiebig
> >>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>>> index 49de476..277a802 100644
> >>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
> >>>>>>>> @@ -27,6 +27,7 @@
> >>>>>>>>  
> >>>>>>>>  #include <linux/cpufreq.h>
> >>>>>>>>  #include <drm/drm_plane_helper.h>
> >>>>>>>> +#include <drm/drm_atomic_helper.h>
> >>>>>>>>  #include "i915_drv.h"
> >>>>>>>>  #include "intel_drv.h"
> >>>>>>>>  #include "../../../platform/x86/intel_ips.h"
> >>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
> >>>>>>>>  				 const struct intel_crtc *intel_crtc,
> >>>>>>>>  				 int level,
> >>>>>>>>  				 struct intel_crtc_state *cstate,
> >>>>>>>> -				 struct intel_plane_state *pristate,
> >>>>>>>> -				 struct intel_plane_state *sprstate,
> >>>>>>>> -				 struct intel_plane_state *curstate,
> >>>>>>>> +				 const struct intel_plane_state *pristate,
> >>>>>>>> +				 const struct intel_plane_state *sprstate,
> >>>>>>>> +				 const struct intel_plane_state *curstate,
> >>>>>>>>  				 struct intel_wm_level *result)
> >>>>>>>>  {
> >>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> >>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>>>>>>>  	struct intel_pipe_wm *pipe_wm;
> >>>>>>>>  	struct drm_device *dev = state->dev;
> >>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
> >>>>>>>> -	struct intel_plane *intel_plane;
> >>>>>>>> -	struct intel_plane_state *pristate = NULL;
> >>>>>>>> -	struct intel_plane_state *sprstate = NULL;
> >>>>>>>> -	struct intel_plane_state *curstate = NULL;
> >>>>>>>> +	struct drm_plane *plane;
> >>>>>>>> +	const struct drm_plane_state *plane_state;
> >>>>>>>> +	const struct intel_plane_state *pristate = NULL;
> >>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
> >>>>>>>> +	const struct intel_plane_state *curstate = NULL;
> >>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
> >>>>>>>>  	struct ilk_wm_maximums max;
> >>>>>>>>  
> >>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
> >>>>>>>>  
> >>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> >>>>>>>> -		struct intel_plane_state *ps;
> >>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> >>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
> >>>>>>>>  
> >>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
> >>>>>>>> -							   intel_plane);
> >>>>>>>> -		if (!ps)
> >>>>>>>> -			continue;
> >>>>>>>> -
> >>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> >>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> >>>>>>>>  			pristate = ps;
> >>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> >>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> >>>>>>>>  			sprstate = ps;
> >>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> >>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
> >>>>>>>>  			curstate = ps;
> >>>>>>>>  	}
> >>>>>>>>  
> >>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>>>>>>>  	if (pipe_wm->sprites_scaled)
> >>>>>>>>  		usable_level = 0;
> >>>>>>>>  
> >>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> >>>>>>>> -
> >>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> >>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> >>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> >>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
> >>>>>>>>  
> >>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> >>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> >>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>>>>>>>  
> >>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
> >>>>>>>>  
> >>>>>>>> -	for (level = 1; level <= max_level; level++) {
> >>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> >>>>>>>> +	for (level = 1; level <= usable_level; level++) {
> >>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
> >>>>>>>>  
> >>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
> >>>>>>>>  				     pristate, sprstate, curstate, wm);
> >>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> >>>>>>>>  		 * register maximums since such watermarks are
> >>>>>>>>  		 * always invalid.
> >>>>>>>>  		 */
> >>>>>>>> -		if (level > usable_level)
> >>>>>>>> -			continue;
> >>>>>>>> -
> >>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
> >>>>>>>> -			pipe_wm->wm[level] = *wm;
> >>>>>>>> -		else
> >>>>>>>> -			usable_level = level;
> >>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
> >>>>>>>> +			memset(wm, 0, sizeof(*wm));
> >>>>>>>> +			break;
> >>>>>>>> +		}
> >>>>>>>>  	}
> >>>>>>>>  
> >>>>>>>>  	return 0;
> >>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>>> index a19ec06..3ce9ba3 100644
> >>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
> >>>>>>>>  
> >>>>>>>>  struct intel_pipe_wm {
> >>>>>>>>  	struct intel_wm_level wm[5];
> >>>>>>>> -	struct intel_wm_level raw_wm[5];
> >>>>>>>>  	uint32_t linetime;
> >>>>>>>>  	bool fbc_wm_enabled;
> >>>>>>>>  	bool pipe_enabled;
> >>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
> >>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
> >>>>>>> 4.9.62.
> >>>>>>>
> >>>>>>> I've cc:ed the authors of that patch now.
> >>>>>>>
> >>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
> >>>>>>> a follow-on patch that resolved this issue in mainline?
> >>>>>>>
> >>>>>>> thanks,
> >>>>>>>
> >>>>>>> greg k-h
> >>>>>>>
> >>>>>> OK, after reverting the patches, the flicker *is* gone.
> >>>>> Thanks for confirming this.
> >>>>>
> >>>>>> BTW (for the future): Was it the right way to address
> >>>>>> stable@vger.kernel.org in this matter or would the bugreport at
> >>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
> >>>>> I have no idea what the i915 developers want, but as far as I'm
> >>>>> concerned, sending this to stable@vger was fine with me, I have no
> >>>>> problem doing a bit of work in tracking down the specific patch before
> >>>>> bugging the developers involved.
> >>>> Well, this one we wanted to be backported, and so indicated with cc:
> >>>> stable, but apparently it went south anyway. :(
> >>>>
> >>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
> >>>> the backport?
> >>>>
> >>>> Maarten?
> >>>>
> >>>> BR,
> >>>> Jani.
> >>>>
> >>>>
> >>> 4.14 is OK, no problems.
> >>>
> >>> So long!
> >>> Rainer Fiebig
> >>
> >> What happens when you apply both other backported patches on top?
> >>
> >> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> >>
> > 
> > So I applied the 2 new patches on top of the orig. 4.9.62.
> > 
> > Better now but not yet completely OK:
> > 
> > ...
> > [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> > [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> > ...
> > 
> > No random flicker so far but flicker when I enter a character in an
> > x-terminal.
> > 
> > Seems your patches fixed only half of the pipes. ;)
> > 
> > So long!
> > Rainer Fiebig
> > 
> 
> There's also random flicker after a while.

Ok, I'm just going to revert this patch for the next release unless one
of the i915 developers has a better idea...

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Thu, Nov 23, 2017 at 10:09:25PM +0100, Rainer Fiebig wrote:
>> Rainer Fiebig wrote:
>>> Maarten Lankhorst wrote:
>>>> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>>>>> Jani Nikula wrote:
>>>>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>>>>> Greg KH wrote:
>>>>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>>>> Hi!
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ...
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>>>>> ...
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The backports are:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>>>>> else OK so far.
>>>>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>>>>> revert it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> thanks,
>>>>>>>>>>>>>
>>>>>>>>>>>>> greg k-h
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>>>>> tree.
>>>>>>>>>>>
>>>>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>>>>> Same here, what git commit id was this?
>>>>>>>>>>>
>>>>>>>>>>> thanks,
>>>>>>>>>>>
>>>>>>>>>>> greg k-h
>>>>>>>>>>>
>>>>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>>>>
>>>>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>>>>
>>>>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>>>>
>>>>>>>>>> So long!
>>>>>>>>>> Rainer Fiebig
>>>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> index 49de476..277a802 100644
>>>>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>>>>  
>>>>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>>>>  #include "i915_drv.h"
>>>>>>>>>>  #include "intel_drv.h"
>>>>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>>>>  				 int level,
>>>>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>>>>  {
>>>>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>>>>> +	struct drm_plane *plane;
>>>>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>>>>  
>>>>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>>>>  
>>>>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>>>>> -		struct intel_plane_state *ps;
>>>>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>>>>  
>>>>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>>>>> -							   intel_plane);
>>>>>>>>>> -		if (!ps)
>>>>>>>>>> -			continue;
>>>>>>>>>> -
>>>>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>>>  			pristate = ps;
>>>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>>>  			sprstate = ps;
>>>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>>>  			curstate = ps;
>>>>>>>>>>  	}
>>>>>>>>>>  
>>>>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>>>>  		usable_level = 0;
>>>>>>>>>>  
>>>>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>>>>> -
>>>>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>>>>  
>>>>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  
>>>>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>>>>  
>>>>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>>>>  
>>>>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>>>>  		 * always invalid.
>>>>>>>>>>  		 */
>>>>>>>>>> -		if (level > usable_level)
>>>>>>>>>> -			continue;
>>>>>>>>>> -
>>>>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>>>>> -		else
>>>>>>>>>> -			usable_level = level;
>>>>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>>>>> +			break;
>>>>>>>>>> +		}
>>>>>>>>>>  	}
>>>>>>>>>>  
>>>>>>>>>>  	return 0;
>>>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>>>>  
>>>>>>>>>>  struct intel_pipe_wm {
>>>>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>>>>  	uint32_t linetime;
>>>>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>>>>  	bool pipe_enabled;
>>>>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>>>>> 4.9.62.
>>>>>>>>>
>>>>>>>>> I've cc:ed the authors of that patch now.
>>>>>>>>>
>>>>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>>>>
>>>>>>>>> thanks,
>>>>>>>>>
>>>>>>>>> greg k-h
>>>>>>>>>
>>>>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>>>>> Thanks for confirming this.
>>>>>>>
>>>>>>>> BTW (for the future): Was it the right way to address
>>>>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>>>>> I have no idea what the i915 developers want, but as far as I'm
>>>>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>>>>> problem doing a bit of work in tracking down the specific patch before
>>>>>>> bugging the developers involved.
>>>>>> Well, this one we wanted to be backported, and so indicated with cc:
>>>>>> stable, but apparently it went south anyway. :(
>>>>>>
>>>>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>>>>> the backport?
>>>>>>
>>>>>> Maarten?
>>>>>>
>>>>>> BR,
>>>>>> Jani.
>>>>>>
>>>>>>
>>>>> 4.14 is OK, no problems.
>>>>>
>>>>> So long!
>>>>> Rainer Fiebig
>>>>
>>>> What happens when you apply both other backported patches on top?
>>>>
>>>> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
>>>>
>>>
>>> So I applied the 2 new patches on top of the orig. 4.9.62.
>>>
>>> Better now but not yet completely OK:
>>>
>>> ...
>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>> ...
>>>
>>> No random flicker so far but flicker when I enter a character in an
>>> x-terminal.
>>>
>>> Seems your patches fixed only half of the pipes. ;)
>>>
>>> So long!
>>> Rainer Fiebig
>>>
>>
>> There's also random flicker after a while.
> 
> Ok, I'm just going to revert this patch for the next release unless one
> of the i915 developers has a better idea...
> 
> thanks,
> 
> greg k-h
> 

Right decision, thanks! I'm still offering to test patches in this
matter once the devs think they've figured it out.

So long!
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Thu, Nov 23, 2017 at 10:09:25PM +0100, Rainer Fiebig wrote:
>> Rainer Fiebig wrote:
>>> Maarten Lankhorst wrote:
>>>> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
>>>>> Jani Nikula wrote:
>>>>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
>>>>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
>>>>>>>> Greg KH wrote:
>>>>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>> Greg KH wrote:
>>>>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>>>>>>>>>>>> Hi!
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hopefully the right addressee.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
>>>>>>>>>>>>>> dmesg shows:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ...
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>>>>>>>>>>>> ...
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The backports are:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>>>>>>     index 49de476..277a802 100644
>>>>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>>>>>>>>>>>> else OK so far.
>>>>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
>>>>>>>>>>>>> revert it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> thanks,
>>>>>>>>>>>>>
>>>>>>>>>>>>> greg k-h
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> I started by reverting the more complex one first ("index
>>>>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
>>>>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
>>>>>>>>>>> tree.
>>>>>>>>>>>
>>>>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>>>>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
>>>>>>>>>>> Same here, what git commit id was this?
>>>>>>>>>>>
>>>>>>>>>>> thanks,
>>>>>>>>>>>
>>>>>>>>>>> greg k-h
>>>>>>>>>>>
>>>>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
>>>>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
>>>>>>>>>>
>>>>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
>>>>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
>>>>>>>>>> reverted the two patches but I'm confident that after having done so the
>>>>>>>>>> flicker will be gone. If not I'll let you know.
>>>>>>>>>>
>>>>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
>>>>>>>>>> patches are part of sort of a package and can not be backported alone.
>>>>>>>>>>
>>>>>>>>>> So long!
>>>>>>>>>> Rainer Fiebig
>>>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> index 49de476..277a802 100644
>>>>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>>>>>>>>> @@ -27,6 +27,7 @@
>>>>>>>>>>  
>>>>>>>>>>  #include <linux/cpufreq.h>
>>>>>>>>>>  #include <drm/drm_plane_helper.h>
>>>>>>>>>> +#include <drm/drm_atomic_helper.h>
>>>>>>>>>>  #include "i915_drv.h"
>>>>>>>>>>  #include "intel_drv.h"
>>>>>>>>>>  #include "../../../platform/x86/intel_ips.h"
>>>>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
>>>>>>>>>>  				 const struct intel_crtc *intel_crtc,
>>>>>>>>>>  				 int level,
>>>>>>>>>>  				 struct intel_crtc_state *cstate,
>>>>>>>>>> -				 struct intel_plane_state *pristate,
>>>>>>>>>> -				 struct intel_plane_state *sprstate,
>>>>>>>>>> -				 struct intel_plane_state *curstate,
>>>>>>>>>> +				 const struct intel_plane_state *pristate,
>>>>>>>>>> +				 const struct intel_plane_state *sprstate,
>>>>>>>>>> +				 const struct intel_plane_state *curstate,
>>>>>>>>>>  				 struct intel_wm_level *result)
>>>>>>>>>>  {
>>>>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
>>>>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  	struct intel_pipe_wm *pipe_wm;
>>>>>>>>>>  	struct drm_device *dev = state->dev;
>>>>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
>>>>>>>>>> -	struct intel_plane *intel_plane;
>>>>>>>>>> -	struct intel_plane_state *pristate = NULL;
>>>>>>>>>> -	struct intel_plane_state *sprstate = NULL;
>>>>>>>>>> -	struct intel_plane_state *curstate = NULL;
>>>>>>>>>> +	struct drm_plane *plane;
>>>>>>>>>> +	const struct drm_plane_state *plane_state;
>>>>>>>>>> +	const struct intel_plane_state *pristate = NULL;
>>>>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
>>>>>>>>>> +	const struct intel_plane_state *curstate = NULL;
>>>>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
>>>>>>>>>>  	struct ilk_wm_maximums max;
>>>>>>>>>>  
>>>>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
>>>>>>>>>>  
>>>>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>>>>>>>>>> -		struct intel_plane_state *ps;
>>>>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
>>>>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>>>>>>>>>>  
>>>>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
>>>>>>>>>> -							   intel_plane);
>>>>>>>>>> -		if (!ps)
>>>>>>>>>> -			continue;
>>>>>>>>>> -
>>>>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
>>>>>>>>>>  			pristate = ps;
>>>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>>>>>>>>>>  			sprstate = ps;
>>>>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
>>>>>>>>>>  			curstate = ps;
>>>>>>>>>>  	}
>>>>>>>>>>  
>>>>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  	if (pipe_wm->sprites_scaled)
>>>>>>>>>>  		usable_level = 0;
>>>>>>>>>>  
>>>>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
>>>>>>>>>> -
>>>>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
>>>>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
>>>>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
>>>>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
>>>>>>>>>>  
>>>>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
>>>>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
>>>>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  
>>>>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
>>>>>>>>>>  
>>>>>>>>>> -	for (level = 1; level <= max_level; level++) {
>>>>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
>>>>>>>>>> +	for (level = 1; level <= usable_level; level++) {
>>>>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
>>>>>>>>>>  
>>>>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
>>>>>>>>>>  				     pristate, sprstate, curstate, wm);
>>>>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>>>>>>>>>>  		 * register maximums since such watermarks are
>>>>>>>>>>  		 * always invalid.
>>>>>>>>>>  		 */
>>>>>>>>>> -		if (level > usable_level)
>>>>>>>>>> -			continue;
>>>>>>>>>> -
>>>>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
>>>>>>>>>> -			pipe_wm->wm[level] = *wm;
>>>>>>>>>> -		else
>>>>>>>>>> -			usable_level = level;
>>>>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
>>>>>>>>>> +			memset(wm, 0, sizeof(*wm));
>>>>>>>>>> +			break;
>>>>>>>>>> +		}
>>>>>>>>>>  	}
>>>>>>>>>>  
>>>>>>>>>>  	return 0;
>>>>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> index a19ec06..3ce9ba3 100644
>>>>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>>>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
>>>>>>>>>>  
>>>>>>>>>>  struct intel_pipe_wm {
>>>>>>>>>>  	struct intel_wm_level wm[5];
>>>>>>>>>> -	struct intel_wm_level raw_wm[5];
>>>>>>>>>>  	uint32_t linetime;
>>>>>>>>>>  	bool fbc_wm_enabled;
>>>>>>>>>>  	bool pipe_enabled;
>>>>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
>>>>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
>>>>>>>>> 4.9.62.
>>>>>>>>>
>>>>>>>>> I've cc:ed the authors of that patch now.
>>>>>>>>>
>>>>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
>>>>>>>>> a follow-on patch that resolved this issue in mainline?
>>>>>>>>>
>>>>>>>>> thanks,
>>>>>>>>>
>>>>>>>>> greg k-h
>>>>>>>>>
>>>>>>>> OK, after reverting the patches, the flicker *is* gone.
>>>>>>> Thanks for confirming this.
>>>>>>>
>>>>>>>> BTW (for the future): Was it the right way to address
>>>>>>>> stable@vger.kernel.org in this matter or would the bugreport at
>>>>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
>>>>>>> I have no idea what the i915 developers want, but as far as I'm
>>>>>>> concerned, sending this to stable@vger was fine with me, I have no
>>>>>>> problem doing a bit of work in tracking down the specific patch before
>>>>>>> bugging the developers involved.
>>>>>> Well, this one we wanted to be backported, and so indicated with cc:
>>>>>> stable, but apparently it went south anyway. :(
>>>>>>
>>>>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
>>>>>> the backport?
>>>>>>
>>>>>> Maarten?
>>>>>>
>>>>>> BR,
>>>>>> Jani.
>>>>>>
>>>>>>
>>>>> 4.14 is OK, no problems.
>>>>>
>>>>> So long!
>>>>> Rainer Fiebig
>>>>
>>>> What happens when you apply both other backported patches on top?
>>>>
>>>> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
>>>>
>>>
>>> So I applied the 2 new patches on top of the orig. 4.9.62.
>>>
>>> Better now but not yet completely OK:
>>>
>>> ...
>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>> ...
>>>
>>> No random flicker so far but flicker when I enter a character in an
>>> x-terminal.
>>>
>>> Seems your patches fixed only half of the pipes. ;)
>>>
>>> So long!
>>> Rainer Fiebig
>>>
>>
>> There's also random flicker after a while.
> 
> Ok, I'm just going to revert this patch for the next release unless one
> of the i915 developers has a better idea...
> 
> thanks,
> 
> greg k-h
> 

I assume this implies that you also revert the two backports for 4.9.62
that startet the problem?

So long!
Rainer Fiebig

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Greg KH]

On Fri, Nov 24, 2017 at 07:48:22AM +0100, Greg KH wrote:
> On Thu, Nov 23, 2017 at 10:09:25PM +0100, Rainer Fiebig wrote:
> > Rainer Fiebig wrote:
> > > Maarten Lankhorst wrote:
> > >> Op 20-11-17 om 09:51 schreef Rainer Fiebig:
> > >>> Jani Nikula wrote:
> > >>>> On Sun, 19 Nov 2017, Greg KH <gregkh@linuxfoundation.org> wrote:
> > >>>>> On Sun, Nov 19, 2017 at 01:44:06PM +0100, Rainer Fiebig wrote:
> > >>>>>> Greg KH wrote:
> > >>>>>>> On Sun, Nov 19, 2017 at 12:56:26PM +0100, Rainer Fiebig wrote:
> > >>>>>>>> Greg KH wrote:
> > >>>>>>>>> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
> > >>>>>>>>>> Greg KH wrote:
> > >>>>>>>>>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
> > >>>>>>>>>>>> Hi!
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> Hopefully the right addressee.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> Encountered two bad backports which cause screen-flicker.
> > >>>>>>>>>>>> dmesg shows:
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> ...
> > >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> > >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> > >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
> > >>>>>>>>>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
> > >>>>>>>>>>>> ...
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> The backports are:
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
> > >>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_pm.c
> > >>>>>>>>>>>>     index 49de476..277a802 100644
> > >>>>>>>>>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > >>>>>>>>>>>> b/drivers/gpu/drm/i915/intel_drv.h
> > >>>>>>>>>>>>     index a19ec06..3ce9ba3 100644
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> After reversing them the flicker is gone, no more messages in dmesg. All
> > >>>>>>>>>>>> else OK so far.
> > >>>>>>>>>>> So which commit was the one that caused the problem?  I will be glad to
> > >>>>>>>>>>> revert it.
> > >>>>>>>>>>>
> > >>>>>>>>>>> thanks,
> > >>>>>>>>>>>
> > >>>>>>>>>>> greg k-h
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>> I started by reverting the more complex one first ("index
> > >>>>>>>>>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> > >>>>>>>>> What git commit id is that?  I don't see those ids in the 4.9-stable
> > >>>>>>>>> tree.
> > >>>>>>>>>
> > >>>>>>>>>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
> > >>>>>>>>>> kernel compiled just fine and the problems were gone (still are).
> > >>>>>>>>> Same here, what git commit id was this?
> > >>>>>>>>>
> > >>>>>>>>> thanks,
> > >>>>>>>>>
> > >>>>>>>>> greg k-h
> > >>>>>>>>>
> > >>>>>>>> OK, no mistake. IIRC, I took the patches (and the IDs) from the
> > >>>>>>>> changelog for patch-4.9.62. I've attached both, so you can check yourself.
> > >>>>>>>>
> > >>>>>>>> I've also applied a freshly downloaded patch-4.9.62 to a freshly
> > >>>>>>>> expanded 4.9 and re-compiled. The flicker is there. I haven't yet
> > >>>>>>>> reverted the two patches but I'm confident that after having done so the
> > >>>>>>>> flicker will be gone. If not I'll let you know.
> > >>>>>>>>
> > >>>>>>>> As a good news: 4.14 is *not* affected. So to me it seems those two
> > >>>>>>>> patches are part of sort of a package and can not be backported alone.
> > >>>>>>>>
> > >>>>>>>> So long!
> > >>>>>>>> Rainer Fiebig
> > >>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > >>>>>>>> index 49de476..277a802 100644
> > >>>>>>>> --- a/drivers/gpu/drm/i915/intel_pm.c
> > >>>>>>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
> > >>>>>>>> @@ -27,6 +27,7 @@
> > >>>>>>>>  
> > >>>>>>>>  #include <linux/cpufreq.h>
> > >>>>>>>>  #include <drm/drm_plane_helper.h>
> > >>>>>>>> +#include <drm/drm_atomic_helper.h>
> > >>>>>>>>  #include "i915_drv.h"
> > >>>>>>>>  #include "intel_drv.h"
> > >>>>>>>>  #include "../../../platform/x86/intel_ips.h"
> > >>>>>>>> @@ -2017,9 +2018,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
> > >>>>>>>>  				 const struct intel_crtc *intel_crtc,
> > >>>>>>>>  				 int level,
> > >>>>>>>>  				 struct intel_crtc_state *cstate,
> > >>>>>>>> -				 struct intel_plane_state *pristate,
> > >>>>>>>> -				 struct intel_plane_state *sprstate,
> > >>>>>>>> -				 struct intel_plane_state *curstate,
> > >>>>>>>> +				 const struct intel_plane_state *pristate,
> > >>>>>>>> +				 const struct intel_plane_state *sprstate,
> > >>>>>>>> +				 const struct intel_plane_state *curstate,
> > >>>>>>>>  				 struct intel_wm_level *result)
> > >>>>>>>>  {
> > >>>>>>>>  	uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> > >>>>>>>> @@ -2341,28 +2342,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> > >>>>>>>>  	struct intel_pipe_wm *pipe_wm;
> > >>>>>>>>  	struct drm_device *dev = state->dev;
> > >>>>>>>>  	const struct drm_i915_private *dev_priv = to_i915(dev);
> > >>>>>>>> -	struct intel_plane *intel_plane;
> > >>>>>>>> -	struct intel_plane_state *pristate = NULL;
> > >>>>>>>> -	struct intel_plane_state *sprstate = NULL;
> > >>>>>>>> -	struct intel_plane_state *curstate = NULL;
> > >>>>>>>> +	struct drm_plane *plane;
> > >>>>>>>> +	const struct drm_plane_state *plane_state;
> > >>>>>>>> +	const struct intel_plane_state *pristate = NULL;
> > >>>>>>>> +	const struct intel_plane_state *sprstate = NULL;
> > >>>>>>>> +	const struct intel_plane_state *curstate = NULL;
> > >>>>>>>>  	int level, max_level = ilk_wm_max_level(dev), usable_level;
> > >>>>>>>>  	struct ilk_wm_maximums max;
> > >>>>>>>>  
> > >>>>>>>>  	pipe_wm = &cstate->wm.ilk.optimal;
> > >>>>>>>>  
> > >>>>>>>> -	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> > >>>>>>>> -		struct intel_plane_state *ps;
> > >>>>>>>> +	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> > >>>>>>>> +		const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
> > >>>>>>>>  
> > >>>>>>>> -		ps = intel_atomic_get_existing_plane_state(state,
> > >>>>>>>> -							   intel_plane);
> > >>>>>>>> -		if (!ps)
> > >>>>>>>> -			continue;
> > >>>>>>>> -
> > >>>>>>>> -		if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> > >>>>>>>> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> > >>>>>>>>  			pristate = ps;
> > >>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> > >>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> > >>>>>>>>  			sprstate = ps;
> > >>>>>>>> -		else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> > >>>>>>>> +		else if (plane->type == DRM_PLANE_TYPE_CURSOR)
> > >>>>>>>>  			curstate = ps;
> > >>>>>>>>  	}
> > >>>>>>>>  
> > >>>>>>>> @@ -2384,11 +2381,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> > >>>>>>>>  	if (pipe_wm->sprites_scaled)
> > >>>>>>>>  		usable_level = 0;
> > >>>>>>>>  
> > >>>>>>>> -	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> > >>>>>>>> -			     pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> > >>>>>>>> -
> > >>>>>>>>  	memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> > >>>>>>>> -	pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> > >>>>>>>> +	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> > >>>>>>>> +			     pristate, sprstate, curstate, &pipe_wm->wm[0]);
> > >>>>>>>>  
> > >>>>>>>>  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> > >>>>>>>>  		pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> > >>>>>>>> @@ -2398,8 +2393,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> > >>>>>>>>  
> > >>>>>>>>  	ilk_compute_wm_reg_maximums(dev, 1, &max);
> > >>>>>>>>  
> > >>>>>>>> -	for (level = 1; level <= max_level; level++) {
> > >>>>>>>> -		struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> > >>>>>>>> +	for (level = 1; level <= usable_level; level++) {
> > >>>>>>>> +		struct intel_wm_level *wm = &pipe_wm->wm[level];
> > >>>>>>>>  
> > >>>>>>>>  		ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
> > >>>>>>>>  				     pristate, sprstate, curstate, wm);
> > >>>>>>>> @@ -2409,13 +2404,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> > >>>>>>>>  		 * register maximums since such watermarks are
> > >>>>>>>>  		 * always invalid.
> > >>>>>>>>  		 */
> > >>>>>>>> -		if (level > usable_level)
> > >>>>>>>> -			continue;
> > >>>>>>>> -
> > >>>>>>>> -		if (ilk_validate_wm_level(level, &max, wm))
> > >>>>>>>> -			pipe_wm->wm[level] = *wm;
> > >>>>>>>> -		else
> > >>>>>>>> -			usable_level = level;
> > >>>>>>>> +		if (!ilk_validate_wm_level(level, &max, wm)) {
> > >>>>>>>> +			memset(wm, 0, sizeof(*wm));
> > >>>>>>>> +			break;
> > >>>>>>>> +		}
> > >>>>>>>>  	}
> > >>>>>>>>  
> > >>>>>>>>  	return 0;
> > >>>>>>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > >>>>>>>> index a19ec06..3ce9ba3 100644
> > >>>>>>>> --- a/drivers/gpu/drm/i915/intel_drv.h
> > >>>>>>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
> > >>>>>>>> @@ -457,7 +457,6 @@ struct intel_crtc_scaler_state {
> > >>>>>>>>  
> > >>>>>>>>  struct intel_pipe_wm {
> > >>>>>>>>  	struct intel_wm_level wm[5];
> > >>>>>>>> -	struct intel_wm_level raw_wm[5];
> > >>>>>>>>  	uint32_t linetime;
> > >>>>>>>>  	bool fbc_wm_enabled;
> > >>>>>>>>  	bool pipe_enabled;
> > >>>>>>> Ok, so this looks like commit 8777b927b92cf5b6c29f9f9d3c737addea9ac8a7
> > >>>>>>> upstream which is commit 7de694782cbe7840f2c0de6f1e70f41fc1b8b6e8 in
> > >>>>>>> 4.9.62.
> > >>>>>>>
> > >>>>>>> I've cc:ed the authors of that patch now.
> > >>>>>>>
> > >>>>>>> Maarten, any hints?  Should I revert this from 4.9-stable, or was there
> > >>>>>>> a follow-on patch that resolved this issue in mainline?
> > >>>>>>>
> > >>>>>>> thanks,
> > >>>>>>>
> > >>>>>>> greg k-h
> > >>>>>>>
> > >>>>>> OK, after reverting the patches, the flicker *is* gone.
> > >>>>> Thanks for confirming this.
> > >>>>>
> > >>>>>> BTW (for the future): Was it the right way to address
> > >>>>>> stable@vger.kernel.org in this matter or would the bugreport at
> > >>>>>> freedesktop.org have been enough? I'm a bit unsure about that.
> > >>>>> I have no idea what the i915 developers want, but as far as I'm
> > >>>>> concerned, sending this to stable@vger was fine with me, I have no
> > >>>>> problem doing a bit of work in tracking down the specific patch before
> > >>>>> bugging the developers involved.
> > >>>> Well, this one we wanted to be backported, and so indicated with cc:
> > >>>> stable, but apparently it went south anyway. :(
> > >>>>
> > >>>> Rainer, does v4.14 work for you? I.e. is the commit okay or not before
> > >>>> the backport?
> > >>>>
> > >>>> Maarten?
> > >>>>
> > >>>> BR,
> > >>>> Jani.
> > >>>>
> > >>>>
> > >>> 4.14 is OK, no problems.
> > >>>
> > >>> So long!
> > >>> Rainer Fiebig
> > >>
> > >> What happens when you apply both other backported patches on top?
> > >>
> > >> https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=v4.9
> > >>
> > > 
> > > So I applied the 2 new patches on top of the orig. 4.9.62.
> > > 
> > > Better now but not yet completely OK:
> > > 
> > > ...
> > > [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
> > > [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
> > > ...
> > > 
> > > No random flicker so far but flicker when I enter a character in an
> > > x-terminal.
> > > 
> > > Seems your patches fixed only half of the pipes. ;)
> > > 
> > > So long!
> > > Rainer Fiebig
> > > 
> > 
> > There's also random flicker after a while.
> 
> Ok, I'm just going to revert this patch for the next release unless one
> of the i915 developers has a better idea...

Now reverted.

thanks,

greg k-h

Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig]

Greg KH wrote:
> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>> Hi!
>>
>> Hopefully the right addressee.
>>
>> Encountered two bad backports which cause screen-flicker.
>> dmesg shows:
>>
>> ...
>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>> ...
>>
>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>
>> The backports are:
>>
>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>> b/drivers/gpu/drm/i915/intel_pm.c
>>     index 49de476..277a802 100644
>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> b/drivers/gpu/drm/i915/intel_drv.h
>>     index a19ec06..3ce9ba3 100644
>>
>> After reversing them the flicker is gone, no more messages in dmesg. All
>> else OK so far.
> 
> So which commit was the one that caused the problem?  I will be glad to
> revert it.
> 
> thanks,
> 
> greg k-h
> 

OK, when reversing only "index 49de476..277a802 100644" the kernel
doesn't compile.

When reversing only "index a19ec06..3ce9ba3 100644" the kernel compiles
but the flicker is there.

Seems those patches are a nasty couple that needs to be removed as such. ;)

So long!
Rainer Fiebig