[PATCH 1/2] drm/i915: Only WARN about a stuck hotplug irq ONCE

[PATCH 1/2] drm/i915: Only WARN about a stuck hotplug irq ONCE

[Chris Wilson]

It seems that hardware that is broken enough to emit a hotplug IRQ even
though the pin is surposedly disable, will do so indefinitely.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1051170
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1051369
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_irq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index ec67bb8aff0a..3be8bcd4d797 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1247,9 +1247,9 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 	spin_lock(&dev_priv->irq_lock);
 	for (i = 1; i < HPD_NUM_PINS; i++) {
 
-		WARN(((hpd[i] & hotplug_trigger) &&
-		      dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED),
-		     "Received HPD interrupt although disabled\n");
+		WARN_ONCE(hpd[i] & hotplug_trigger &&
+			  dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED,
+			  "Received HPD interrupt although disabled\n");
 
 		if (!(hpd[i] & hotplug_trigger) ||
 		    dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)
-- 
1.8.5.2

[PATCH 2/2] drm/i915: Only complain about a rogue hotplug IRQ after disabling

[Chris Wilson]

Disabling the hotplug IRQ is a two-step process. First, inside the IRQ
handler we mark the rogue hotplug pin for disabling. Then later in the
hotplug worker, we actually disable the hotplug pin. So we should not
WARN about the rogue hotplug IRQ being sent until after we have
completed disabling the pin.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1051170
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 3be8bcd4d797..b38a375fc48f 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1248,7 +1248,7 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 	for (i = 1; i < HPD_NUM_PINS; i++) {
 
 		WARN_ONCE(hpd[i] & hotplug_trigger &&
-			  dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED,
+			  dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED,
 			  "Received HPD interrupt although disabled\n");
 
 		if (!(hpd[i] & hotplug_trigger) ||
-- 
1.8.5.2

Re: [PATCH 1/2] drm/i915: Only WARN about a stuck hotplug irq ONCE

[Chris Wilson]

On Fri, Jan 10, 2014 at 06:49:20PM +0000, Chris Wilson wrote:
> It seems that hardware that is broken enough to emit a hotplug IRQ even
> though the pin is surposedly disable, will do so indefinitely.
> 
> References: https://bugzilla.redhat.com/show_bug.cgi?id=1051170
> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1051369

Wrong URL, should have been
Link: https://bugzilla.redhat.com/attachment.cgi?id=847786
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

Re: [PATCH 1/2] drm/i915: Only WARN about a stuck hotplug irq ONCE

[Daniel Vetter]

On Fri, Jan 10, 2014 at 06:49:20PM +0000, Chris Wilson wrote:
> It seems that hardware that is broken enough to emit a hotplug IRQ even
> though the pin is surposedly disable, will do so indefinitely.
> 
> References: https://bugzilla.redhat.com/show_bug.cgi?id=1051170
> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1051369
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

gm45, unsurprisingly ... Underlying cause should be fixed with

commit 0ce99f749b3834edeb500e17d6ad17e86b60ff83
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jul 26 11:27:49 2013 +0200

    drm/i915: fix gen4 digital port hotplug definitions

Or at least that's my hope. For further debug help, care to also dump the
hotplug_trigger bits in the format string while at it?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_irq.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index ec67bb8aff0a..3be8bcd4d797 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1247,9 +1247,9 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
>  	spin_lock(&dev_priv->irq_lock);
>  	for (i = 1; i < HPD_NUM_PINS; i++) {
>  
> -		WARN(((hpd[i] & hotplug_trigger) &&
> -		      dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED),
> -		     "Received HPD interrupt although disabled\n");
> +		WARN_ONCE(hpd[i] & hotplug_trigger &&
> +			  dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED,
> +			  "Received HPD interrupt although disabled\n");
>  
>  		if (!(hpd[i] & hotplug_trigger) ||
>  		    dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)
> -- 
> 1.8.5.2
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

[PATCH] drm/i915: Include more information in disabled hotplug interrupt warning

[Chris Wilson]

Daniel thought that this was an opportune moment to include which pins
and bits ended up being stuck in the WARN.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_irq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b38a375fc48f..7818a57f2fa4 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1249,7 +1249,8 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 
 		WARN_ONCE(hpd[i] & hotplug_trigger &&
 			  dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED,
-			  "Received HPD interrupt although disabled\n");
+			  "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n",
+			  hotplug_trigger, i, hpd[i]);
 
 		if (!(hpd[i] & hotplug_trigger) ||
 		    dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)
-- 
1.8.5.2