Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Daniel Vetter]

On Fri, Nov 22, 2013 at 12:01 PM, Keith Packard <keithp@keithp.com> wrote:
> Daniel Vetter <daniel@ffwll.ch> writes:
>
>> Hm, where do we have the canonical source for all these fourcc codes? I'm
>> asking since we have our own copy in the kernel as drm_fourcc.h, and that
>> one is part of the userspace ABI since we use it to pass around
>> framebuffer formats and format lists.
>
> I think it's the kernel? I really don't know, as the whole notion of
> fourcc codes seems crazy to me...
>
> Feel free to steal this code and stick it in the kernel if you like.

Well, I wasn't ever in favour of using fourcc codes since they're just
not standardized at all, highly redundant in some cases and also miss
lots of stuff we actually need (like all the rgb formats).

Cc'ing the heck out of this to get kernel people to hopefully notice.
Maybe someone takes charge of this ... Otherwise meh.

>> Just afraid to create long-term maintainance madness here with the
>> kernel's iron thou-shalt-not-break-userspace-ever rule ... Not likely
>> we'll ever accept srgb for framebuffers though.
>
> Would suck to collide with something we do want though.

Yeah, it'd suck. But given how fourcc works we probably have that
already, just haven't noticed yet :(
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Ville Syrjälä]

On Fri, Nov 22, 2013 at 05:17:37PM +0100, Daniel Vetter wrote:
> On Fri, Nov 22, 2013 at 12:01 PM, Keith Packard <keithp@keithp.com> wrote:
> > Daniel Vetter <daniel@ffwll.ch> writes:
> >
> >> Hm, where do we have the canonical source for all these fourcc codes? I'm
> >> asking since we have our own copy in the kernel as drm_fourcc.h, and that
> >> one is part of the userspace ABI since we use it to pass around
> >> framebuffer formats and format lists.
> >
> > I think it's the kernel? I really don't know, as the whole notion of
> > fourcc codes seems crazy to me...
> >
> > Feel free to steal this code and stick it in the kernel if you like.
> 
> Well, I wasn't ever in favour of using fourcc codes since they're just
> not standardized at all, highly redundant in some cases and also miss
> lots of stuff we actually need (like all the rgb formats).

I also argued against them, but some people wanted them for whatever
reason. And since I didn't want to argue for several years about the
subject, I just gave in and made the drm pixel formats fourcss. But
given that I just pulled the fourccs out of my ass, we can't really
cross use them between different subsystems anyway. So if we just
consider all the different fourcc namespaces totally distinct, we're
not going to have any problems.

Personally I can promise that I will _not_ be checking Mesa/whatever
code for conflicting fourccs when I need to add a new one to drm_fourcc.h.
There, now I've given fair warning and if things explode later it won't be
my fault.

However if someone wants to emulate the drm fourcc style for whatever
reason, there is a distinct pattern how I cooked them up. Well, a few
different patterns depending whether it's RGB,YUV,packed,planar etc.

> 
> Cc'ing the heck out of this to get kernel people to hopefully notice.
> Maybe someone takes charge of this ... Otherwise meh.
> 
> >> Just afraid to create long-term maintainance madness here with the
> >> kernel's iron thou-shalt-not-break-userspace-ever rule ... Not likely
> >> we'll ever accept srgb for framebuffers though.
> >
> > Would suck to collide with something we do want though.
> 
> Yeah, it'd suck. But given how fourcc works we probably have that
> already, just haven't noticed yet :(
> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel OTC

Re: [Intel-gfx] [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Kristian Høgsberg]

On Fri, Nov 22, 2013 at 05:17:37PM +0100, Daniel Vetter wrote:
> On Fri, Nov 22, 2013 at 12:01 PM, Keith Packard <keithp@keithp.com> wrote:
> > Daniel Vetter <daniel@ffwll.ch> writes:
> >
> >> Hm, where do we have the canonical source for all these fourcc codes? I'm
> >> asking since we have our own copy in the kernel as drm_fourcc.h, and that
> >> one is part of the userspace ABI since we use it to pass around
> >> framebuffer formats and format lists.
> >
> > I think it's the kernel? I really don't know, as the whole notion of
> > fourcc codes seems crazy to me...
> >
> > Feel free to steal this code and stick it in the kernel if you like.
> 
> Well, I wasn't ever in favour of using fourcc codes since they're just
> not standardized at all, highly redundant in some cases and also miss
> lots of stuff we actually need (like all the rgb formats).

These drm codes are not fourcc codes in any other way than that
they're defined by creating a 32 bit value by picking four characters.
I don't know what PTSD triggers people have from hearing "fourcc", but
it seems severe.  Forget all that, these codes are DRM specific
defines that are not inteded to match anything anybody else does.  It
doesn't matter if these match of conflict with v4l, fourcc.org,
wikipedia.org or what the amiga did.  They're just tokens that let us
define succintly what the pixel format of a kms framebuffer is and
tell the kernel.

I don't know what else you'd propose?  Pass an X visual in the ioctl?
An EGL config?  This is our name space, we can add stuff as we need
(as Keith is doing here). include/uapi/drm/drm_fourcc.h is the
canonical source for these values and we should add
DRM_FORMAT_SARGB8888 there to make sure we don't clash.

Why are these codes in mesa (and gbm and wl_drm protocol) then?
Because it turns out that once you have an stable and established
namespace for pixel formats (and a kernel userspace header is about as
stable and established as it gets) it makes a lot of sense to reuse
those values.

I already explained to Keith why we use different sets of format codes
in the DRI interface, but it's always fun to slam other peoples code.
Anyway, it's pretty simple, the __DRI_IMAGE_FORMAT_* defines predate
the introduction of drm_fourcc.h.  When we later added suport for
planar YUV __DRIimages, the kernel had picked up drm_fourcc.h after a
long sad bikeshedding flamewar, which included the planar formats we
needed.  At this point we could continue using our custom
__DRI_IMAGE_FORMAT_* defines or we could switch to the tokens that we
had finally converged on.  But don't let me ruin a good old snide remark.

> Cc'ing the heck out of this to get kernel people to hopefully notice.
> Maybe someone takes charge of this ... Otherwise meh.

I don't know what you want to change.  These values are already kernel
ABI, we use them in drmAddFB2, and again, I don't understand what
problem you're seeing.

Kristian

> >> Just afraid to create long-term maintainance madness here with the
> >> kernel's iron thou-shalt-not-break-userspace-ever rule ... Not likely
> >> we'll ever accept srgb for framebuffers though.
> >
> > Would suck to collide with something we do want though.
> 
> Yeah, it'd suck. But given how fourcc works we probably have that
> already, just haven't noticed yet :(
> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [Intel-gfx] [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Ville Syrjälä]

On Fri, Nov 22, 2013 at 02:12:13PM -0800, Kristian Høgsberg wrote:
> On Fri, Nov 22, 2013 at 05:17:37PM +0100, Daniel Vetter wrote:
> > On Fri, Nov 22, 2013 at 12:01 PM, Keith Packard <keithp@keithp.com> wrote:
> > > Daniel Vetter <daniel@ffwll.ch> writes:
> > >
> > >> Hm, where do we have the canonical source for all these fourcc codes? I'm
> > >> asking since we have our own copy in the kernel as drm_fourcc.h, and that
> > >> one is part of the userspace ABI since we use it to pass around
> > >> framebuffer formats and format lists.
> > >
> > > I think it's the kernel? I really don't know, as the whole notion of
> > > fourcc codes seems crazy to me...
> > >
> > > Feel free to steal this code and stick it in the kernel if you like.
> > 
> > Well, I wasn't ever in favour of using fourcc codes since they're just
> > not standardized at all, highly redundant in some cases and also miss
> > lots of stuff we actually need (like all the rgb formats).
> 
> These drm codes are not fourcc codes in any other way than that
> they're defined by creating a 32 bit value by picking four characters.
> I don't know what PTSD triggers people have from hearing "fourcc", but
> it seems severe.  Forget all that, these codes are DRM specific
> defines that are not inteded to match anything anybody else does.  It
> doesn't matter if these match of conflict with v4l, fourcc.org,
> wikipedia.org or what the amiga did.  They're just tokens that let us
> define succintly what the pixel format of a kms framebuffer is and
> tell the kernel.
> 
> I don't know what else you'd propose?  Pass an X visual in the ioctl?
> An EGL config?  This is our name space, we can add stuff as we need
> (as Keith is doing here). include/uapi/drm/drm_fourcc.h is the
> canonical source for these values and we should add
> DRM_FORMAT_SARGB8888 there to make sure we don't clash.

What is this format anyway? -ENODOCS

If its just an srgb version of ARGB8888, then I wouldn't really want it
in drm_fourcc.h. I expect colorspacy stuff will be handled by various
crtc/plane properties in the kernel so we don't need to encode that
stuff into the fb format.

-- 
Ville Syrjälä
Intel OTC

Re: [Intel-gfx] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Keith Packard]

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Kristian Høgsberg <hoegsberg@gmail.com> writes:

> I already explained to Keith why we use different sets of format codes
> in the DRI interface, but it's always fun to slam other peoples code.

As we discussed, my complaint isn't so much about __DRI_IMAGE_FOURCC,
but the fact that the __DRIimage interfaces use *both*
__DRI_IMAGE_FOURCC and __DRI_IMAGE_FORMAT at different times.

Ok, here's a fine thing we can actually fix -- the pattern that mesa
uses all over the place in converting formats looks like this (not to
pick on anyone, it's repeated everywhere, this is just the first one I
found in gbm_dri.c):

	static uint32_t
        gbm_dri_to_gbm_format(uint32_t dri_format)
	{
	   uint32_t ret = 0;
	
	   switch (dri_format) {
	   case __DRI_IMAGE_FORMAT_RGB565:
	      ret = GBM_FORMAT_RGB565;
	      break;
	   case __DRI_IMAGE_FORMAT_XRGB8888:
	      ret = GBM_FORMAT_XRGB8888;
	      break;
	   case __DRI_IMAGE_FORMAT_ARGB8888:
	      ret = GBM_FORMAT_ARGB8888;
	      break;
	   case __DRI_IMAGE_FORMAT_ABGR8888:
	      ret = GBM_FORMAT_ABGR8888;
	      break;
	   default:
	      ret = 0;
	      break;
	   }
	
	   return ret;
	}

The problem here is that any unknown incoming formats get translated to
garbage (0) outgoing. With fourcc codes, there is the slight advantage
that 0 is never a legal value, but it sure would be nice to print a
warning or even abort if you get a format code you don't understand as
there's no way 0 is ever going to do what you want.

Anyone have a preference? Abort? Print an error? Silently continue to do
the wrong thing?

-- 
keith.packard@intel.com

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Re: [Intel-gfx] [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Keith Packard]

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Ville Syrjälä <ville.syrjala@linux.intel.com> writes:

> What is this format anyway? -ENODOCS

Same as MESA_FORMAT_SARGB8 and __DRI_IMAGE_FORMAT_SARGB8 :-)

> If its just an srgb version of ARGB8888, then I wouldn't really want it
> in drm_fourcc.h. I expect colorspacy stuff will be handled by various
> crtc/plane properties in the kernel so we don't need to encode that
> stuff into the fb format.

It's not any different from splitting YUV codes from RGB codes; a
different color encoding with the same bitfields. And, for mesa, it's
necessary to differentiate between ARGB and SARGB within the same format
code given how the API is structured. So, we have choices:

 1) Let Mesa define it's own fourcc codes and risk future accidental
    collisions
 
 2) Rewrite piles of mesa code to split out the color encoding from the
    bitfield information and pass it separately.

 3) Add "reasonable" format codes like this to the kernel fourcc list.

-- 
keith.packard@intel.com

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Re: [Intel-gfx] [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Ville Syrjälä]

On Fri, Nov 22, 2013 at 03:43:13PM -0800, Keith Packard wrote:
> Ville Syrjälä <ville.syrjala@linux.intel.com> writes:
> 
> > What is this format anyway? -ENODOCS
> 
> Same as MESA_FORMAT_SARGB8 and __DRI_IMAGE_FORMAT_SARGB8 :-)
> 
> > If its just an srgb version of ARGB8888, then I wouldn't really want it
> > in drm_fourcc.h. I expect colorspacy stuff will be handled by various
> > crtc/plane properties in the kernel so we don't need to encode that
> > stuff into the fb format.
> 
> It's not any different from splitting YUV codes from RGB codes;

Not really. Saying something is YUV (or rather Y'CbCr) doesn't
actually tell you the color space. It just tells you whether the
information is encoded as R+G+B or Y+Cb+Cr. How you convert between
them is another matter. You need to know the gamma, color primaries,
chroma siting for sub-sampled YCbCr formats, etc.

-- 
Ville Syrjälä
Intel OTC

Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Daniel Vetter]

On Fri, Nov 22, 2013 at 02:12:13PM -0800, Kristian Høgsberg wrote:
> I don't know what else you'd propose?  Pass an X visual in the ioctl?
> An EGL config?  This is our name space, we can add stuff as we need
> (as Keith is doing here). include/uapi/drm/drm_fourcc.h is the
> canonical source for these values and we should add
> DRM_FORMAT_SARGB8888 there to make sure we don't clash.

Well that's kinda the problem. If you don't expect the kernel to clash
with whatever mesa is using internally then we should add it to the
kernel, first. That's kinda what Dave's recent rant has all been about.

The other issue was that originally the idea behind fourcc was to have one
formate namespace shared between drm, v4l and whomever else cares. If
people are happy to drop that idea on the floor I won't shed a single
tear.

In the end I'll expect that someone will make a funny collision between
all the different projects anyway, so meh.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Ville Syrjälä]

On Mon, Nov 25, 2013 at 09:57:23AM +0100, Daniel Vetter wrote:
> On Fri, Nov 22, 2013 at 02:12:13PM -0800, Kristian Høgsberg wrote:
> > I don't know what else you'd propose?  Pass an X visual in the ioctl?
> > An EGL config?  This is our name space, we can add stuff as we need
> > (as Keith is doing here). include/uapi/drm/drm_fourcc.h is the
> > canonical source for these values and we should add
> > DRM_FORMAT_SARGB8888 there to make sure we don't clash.
> 
> Well that's kinda the problem. If you don't expect the kernel to clash
> with whatever mesa is using internally then we should add it to the
> kernel, first. That's kinda what Dave's recent rant has all been about.
> 
> The other issue was that originally the idea behind fourcc was to have one
> formate namespace shared between drm, v4l and whomever else cares. If
> people are happy to drop that idea on the floor I won't shed a single
> tear.

I broke that idea alredy when I cooked up the current drm fourccs.
I didn't cross check them with any other fourcc source, so I'm 100%
sure most of them don't match anything else.

-- 
Ville Syrjälä
Intel OTC

Re: [Mesa-dev] [PATCH] dri3, i915, i965: Add __DRI_IMAGE_FOURCC_SARGB8888

[Geert Uytterhoeven]

On Sat, Nov 23, 2013 at 2:10 AM, Ville Syrjälä
<ville.syrjala@linux.intel.com> wrote:
> On Fri, Nov 22, 2013 at 03:43:13PM -0800, Keith Packard wrote:
>> Ville Syrjälä <ville.syrjala@linux.intel.com> writes:
>>
>> > What is this format anyway? -ENODOCS
>>
>> Same as MESA_FORMAT_SARGB8 and __DRI_IMAGE_FORMAT_SARGB8 :-)
>>
>> > If its just an srgb version of ARGB8888, then I wouldn't really want it
>> > in drm_fourcc.h. I expect colorspacy stuff will be handled by various
>> > crtc/plane properties in the kernel so we don't need to encode that
>> > stuff into the fb format.
>>
>> It's not any different from splitting YUV codes from RGB codes;
>
> Not really. Saying something is YUV (or rather Y'CbCr) doesn't
> actually tell you the color space. It just tells you whether the
> information is encoded as R+G+B or Y+Cb+Cr. How you convert between
> them is another matter. You need to know the gamma, color primaries,
> chroma siting for sub-sampled YCbCr formats, etc.

Yep. Fbdev has a separation of type (how pixel values are laid out in memory),
fb_bitfield structs (how tuples are formed into pixels), and visual (how to
interprete the tuples).

The fb_bitfield structs do have RGB-centric names, but you could use them
for e.g. Y, Cb, Cr, and alpha, giving a proper visual. Unfortunately the
YCbCr visuals haven't made it into mainline.

FOURCC unifies all of that in (not so) unique 32-bit IDs.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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i830 watermark problems - status?

[Thomas Richter]

Hi Daniel, hi group,

just being curious - what is the status of the i830 watermark problems, 
i.e. the state of affairs
concerning that the i830 does not allow the maximum watermark value, but 
requires a "headroom" of eight entries to
avoid flickering.

I provided a patch for this a while ago, but this seems to go nowhere. 
Just to remind you: The current code does not create
a stable image on i830 based devices, even if only an internal display 
is connected.

I provided two possible attacks to the problem: A quick and dirty method 
which checks for the maximum value for
i830 manually, or an overall solution which adds a "minimum" watermark 
value for all supported chipsets.

Please let me know how to proceed.

Thanks,
     Thomas

Re: i830 watermark problems - status?

[Daniel Vetter]

On Mon, Nov 25, 2013 at 04:14:12PM +0100, Thomas Richter wrote:
> Hi Daniel, hi group,
> 
> just being curious - what is the status of the i830 watermark
> problems, i.e. the state of affairs
> concerning that the i830 does not allow the maximum watermark value,
> but requires a "headroom" of eight entries to
> avoid flickering.
> 
> I provided a patch for this a while ago, but this seems to go
> nowhere. Just to remind you: The current code does not create
> a stable image on i830 based devices, even if only an internal
> display is connected.
> 
> I provided two possible attacks to the problem: A quick and dirty
> method which checks for the maximum value for
> i830 manually, or an overall solution which adds a "minimum"
> watermark value for all supported chipsets.
> 
> Please let me know how to proceed.

I seem to be too swamped with firedrills and bugs atm to get the polished
version in. The problem with just a quick hack is that we still need to
switch i830M to the dual-pipe watermark function, and somehow my patch to
do so seems to be broken. At least you've said that the kernel still seems
to hit the single-watermark version of the function.

So atm I'm a bit stalled on this :( But if you can track this down I'd go
with a quick hack to enforce the minimum of 8 or so in the dual-pipe
watermark function shared by gen2/3.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: i830 watermark problems - status?

[Thomas Richter]

Am 25.11.2013 16:23, schrieb Daniel Vetter:
> On Mon, Nov 25, 2013 at 04:14:12PM +0100, Thomas Richter wrote:
>> Hi Daniel, hi group,
>>
>> just being curious - what is the status of the i830 watermark
>> problems, i.e. the state of affairs
>> concerning that the i830 does not allow the maximum watermark value,
>> but requires a "headroom" of eight entries to
>> avoid flickering.
>>
>> I provided a patch for this a while ago, but this seems to go
>> nowhere. Just to remind you: The current code does not create
>> a stable image on i830 based devices, even if only an internal
>> display is connected.
>>
>> I provided two possible attacks to the problem: A quick and dirty
>> method which checks for the maximum value for
>> i830 manually, or an overall solution which adds a "minimum"
>> watermark value for all supported chipsets.
>>
>> Please let me know how to proceed.
> I seem to be too swamped with firedrills and bugs atm to get the polished
> version in. The problem with just a quick hack is that we still need to
> switch i830M to the dual-pipe watermark function, and somehow my patch to
> do so seems to be broken. At least you've said that the kernel still seems
> to hit the single-watermark version of the function.
>
> So atm I'm a bit stalled on this :( But if you can track this down I'd go
> with a quick hack to enforce the minimum of 8 or so in the dual-pipe
> watermark function shared by gen2/3.

Not a problem on my side, but it would be a "bad thing"(tm) to release a 
kernel that leaves a i830 based
architecture essentially non-usable. Well, if you depend on a local 
display, that is. (-;

Greetings,
     Thomas

Re: i830 watermark problems - status?

[Daniel Vetter]

On Mon, Nov 25, 2013 at 4:55 PM, Thomas Richter <thor@math.tu-berlin.de> wrote:
> Am 25.11.2013 16:23, schrieb Daniel Vetter:
>>
>> On Mon, Nov 25, 2013 at 04:14:12PM +0100, Thomas Richter wrote:
>>>
>>> Hi Daniel, hi group,
>>>
>>> just being curious - what is the status of the i830 watermark
>>> problems, i.e. the state of affairs
>>> concerning that the i830 does not allow the maximum watermark value,
>>> but requires a "headroom" of eight entries to
>>> avoid flickering.
>>>
>>> I provided a patch for this a while ago, but this seems to go
>>> nowhere. Just to remind you: The current code does not create
>>> a stable image on i830 based devices, even if only an internal
>>> display is connected.
>>>
>>> I provided two possible attacks to the problem: A quick and dirty
>>> method which checks for the maximum value for
>>> i830 manually, or an overall solution which adds a "minimum"
>>> watermark value for all supported chipsets.
>>>
>>> Please let me know how to proceed.
>>
>> I seem to be too swamped with firedrills and bugs atm to get the polished
>>
>> version in. The problem with just a quick hack is that we still need to
>> switch i830M to the dual-pipe watermark function, and somehow my patch to
>> do so seems to be broken. At least you've said that the kernel still seems
>> to hit the single-watermark version of the function.
>>
>> So atm I'm a bit stalled on this :( But if you can track this down I'd go
>> with a quick hack to enforce the minimum of 8 or so in the dual-pipe
>> watermark function shared by gen2/3.
>
>
> Not a problem on my side, but it would be a "bad thing"(tm) to release a
> kernel that leaves a i830 based
> architecture essentially non-usable. Well, if you depend on a local display,
> that is. (-;

Well i830M has been broken since forever, so in a way this is just
normal enabling. Since you're the first guy to actually bother with it
I don't think the actual population of i830M users is that big ... So
imo we don't need to be in an utter hurry to rush in something which
isn't ready.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: i830 watermark problems - status?

[Thomas Richter]

Hi Daniel,

just a short notice that I tried the same patch - namely adjusting the 
minimum watermark value (thus the maximual watermark setting) now on the 
i830 based Fujitsu, and it does work here as well as it did on the R31. 
Thus, this seems to be the real culprit.

This is the laptop with the strange DVO lockup syndrom.

So long,
	Thomas

intel-drm-nightly: hang and black screen on i830

[Thomas Richter]

Hi Daniel, hi folks,

back from a couple of business trips, so finally some time to look into 
the i830 support on this old laptop.

Sorry to say that the current drm-nightly does not work at all. It just 
generates a hang, resulting in a black screen and nothing else. All you 
can do there is to turn the machine off the hard way.

Here is what I get in the kernel log: Probably 
intel_modeset_setup_hw_state hangs? Hard to say.

Dec 19 14:38:50 tyleet kernel: [  240.296074] INFO: task modprobe:439 
blocked for more than 120 seconds.
Dec 19 14:38:50 tyleet kernel: [  240.296091]       Not tainted 
3.13.0-rc3+ #2
Dec 19 14:38:50 tyleet kernel: [  240.296097] "echo 0 > 
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Dec 19 14:38:50 tyleet kernel: [  240.296104] modprobe        D 
f6145bc0     0   439    375 0x00000004
Dec 19 14:38:50 tyleet kernel: [  240.296117]  f60b0360 00000082 
c1302256 f6145bc0 f6145ba6 00000002 00000000 f60b0360
Dec 19 14:38:50 tyleet kernel: [  240.296132]  f84c3771 f84c3771 
f84c73a3 f84c73a4 c11803c1 00000001 00000000 c103ff02
Dec 19 14:38:50 tyleet kernel: [  240.296147]  00004e0a f061ffff 
f84affff f84c376e 00000000 f84c73a3 02145b48 f84c73c0
Dec 19 14:38:50 tyleet kernel: [  240.296161] Call Trace:
Dec 19 14:38:50 tyleet kernel: [  240.296181]  [<c1302256>] ? 
__schedule+0x166/0x410
Dec 19 14:38:50 tyleet kernel: [  240.296218]  [<c11803c1>] ? 
vsnprintf+0xd1/0x5c0
Dec 19 14:38:50 tyleet kernel: [  240.296233]  [<c103ff02>] ? 
do_sigaction+0x62/0x160
Dec 19 14:38:50 tyleet kernel: [  240.296268]  [<f84affff>] ? 
drm_mode_gamma_get_ioctl+0xbf/0xe0 [drm]
Dec 19 14:38:50 tyleet kernel: [  240.296285]  [<c13026a5>] ? 
schedule_preempt_disabled+0x5/0x10
Dec 19 14:38:50 tyleet kernel: [  240.296296]  [<c13035bb>] ? 
__mutex_lock_slowpath+0x4b/0x7a
Dec 19 14:38:50 tyleet kernel: [  240.296306]  [<c1303123>] ? 
mutex_lock+0x13/0x15
Dec 19 14:38:50 tyleet kernel: [  240.296422]  [<f8dc5b12>] ? 
intel_get_load_detect_pipe+0x152/0x3e0 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296515]  [<f8de59a4>] ? 
intel_update_watermarks+0x14/0x20 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296585]  [<f8dba9ee>] ? 
i9xx_crtc_disable+0x19e/0x2f0 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296658]  [<f8dc79ef>] ? 
intel_modeset_setup_hw_state+0xadf/0xb90 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296676]  [<c1300001>] ? 
remove_waiter+0x9d/0xd3
Dec 19 14:38:50 tyleet kernel: [  240.296759]  [<f8df6d00>] ? 
gen4_write16+0x20/0x20 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296817]  [<f8d92b40>] ? 
i915_semaphore_is_enabled+0x50/0x50 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296888]  [<f8dc7ac6>] ? 
intel_modeset_gem_init+0x26/0x30 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.296947]  [<f8d95dea>] ? 
i915_driver_load+0xcca/0xe60 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.297004]  [<f8d932d0>] ? 
i915_dma_init+0x2e0/0x2e0 [i915]
Dec 19 14:38:50 tyleet kernel: [  240.297034]  [<c1213709>] ? 
device_add+0x159/0x510
Dec 19 14:38:50 tyleet kernel: [  240.297071]  [<f84a5f63>] ? 
drm_dev_register+0x83/0x1b0 [drm]
Dec 19 14:38:50 tyleet kernel: [  240.297095]  [<f84a7b88>] ? 
drm_get_pci_dev+0x88/0x140 [drm]
Dec 19 14:38:50 tyleet kernel: [  240.297113]  [<c111cf59>] ? 
sysfs_do_create_link_sd.isra.5+0x99/0x1b0
Dec 19 14:38:50 tyleet kernel: [  240.297126]  [<c11a17ef>] ? 
pci_device_probe+0x7f/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297138]  [<c1215e30>] ? 
driver_probe_device+0x1f0/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297148]  [<c111d08d>] ? 
sysfs_create_link+0x1d/0x40
Dec 19 14:38:50 tyleet kernel: [  240.297159]  [<c1215e30>] ? 
driver_probe_device+0x1f0/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297169]  [<c1215c93>] ? 
driver_probe_device+0x53/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297180]  [<c1179ed8>] ? 
kobject_add_internal+0x158/0x210
Dec 19 14:38:50 tyleet kernel: [  240.297191]  [<c1215ea9>] ? 
__driver_attach+0x79/0x80
Dec 19 14:38:50 tyleet kernel: [  240.297204]  [<c1214698>] ? 
bus_for_each_dev+0x38/0x70
Dec 19 14:38:50 tyleet kernel: [  240.297214]  [<c1215876>] ? 
driver_attach+0x16/0x20
Dec 19 14:38:50 tyleet kernel: [  240.297223]  [<c1215e30>] ? 
driver_probe_device+0x1f0/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297232]  [<c1215521>] ? 
bus_add_driver+0xe1/0x1e0
Dec 19 14:38:50 tyleet kernel: [  240.297244]  [<c1216401>] ? 
driver_register+0x51/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297266]  [<f8e2d000>] ? 0xf8e2cfff
Dec 19 14:38:50 tyleet kernel: [  240.297277]  [<f8e2d000>] ? 0xf8e2cfff
Dec 19 14:38:50 tyleet kernel: [  240.297287]  [<c1000462>] ? 
do_one_initcall+0xe2/0x130
Dec 19 14:38:50 tyleet kernel: [  240.297297]  [<c1303118>] ? 
mutex_lock+0x8/0x15
Dec 19 14:38:50 tyleet kernel: [  240.297308]  [<c1093a55>] ? 
jump_label_module_notify+0x155/0x1a0
Dec 19 14:38:50 tyleet kernel: [  240.297322]  [<c104e890>] ? 
notifier_call_chain+0x40/0x60
Dec 19 14:38:50 tyleet kernel: [  240.297335]  [<c104eadb>] ? 
__blocking_notifier_call_chain+0x4b/0x70
Dec 19 14:38:50 tyleet kernel: [  240.297348]  [<c107c988>] ? 
load_module+0x1a18/0x2160
Dec 19 14:38:50 tyleet kernel: [  240.297369]  [<c102d920>] ? 
vmalloc_sync_all+0xd0/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297381]  [<c107d161>] ? 
SyS_init_module+0x91/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297403]  [<c130489e>] ? 
sysenter_do_call+0x12/0x26

Dec 19 14:38:50 tyleet kernel: [  240.297412] INFO: task modprobe:449 
blocked for more than 120 seconds.
Dec 19 14:38:50 tyleet kernel: [  240.297419]       Not tainted 
3.13.0-rc3+ #2
Dec 19 14:38:50 tyleet kernel: [  240.297425] "echo 0 > 
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Dec 19 14:38:50 tyleet kernel: [  240.297430] modprobe        D 
f6831c40     0   449    393 0x00000004
Dec 19 14:38:50 tyleet kernel: [  240.297441]  f61c0d80 00000086 
c111bd5a f6831c40 f627e600 f627e600 c111c3ce f61c0d80
Dec 19 14:38:50 tyleet kernel: [  240.297456]  c111c2d6 f627e600 
00000001 f609ca40 c111c553 f627e600 f6831c40 f627e600
Dec 19 14:38:50 tyleet kernel: [  240.297470]  f627e600 00000000 
f6831c40 f62faea0 c111c653 00000000 f62faea0 00000000
Dec 19 14:38:50 tyleet kernel: [  240.297484] Call Trace:
Dec 19 14:38:50 tyleet kernel: [  240.297496]  [<c111bd5a>] ? 
sysfs_link_sibling+0x6a/0xb0
Dec 19 14:38:50 tyleet kernel: [  240.297506]  [<c111c3ce>] ? 
__sysfs_add_one+0x4e/0xf0
Dec 19 14:38:50 tyleet kernel: [  240.297516]  [<c111c2d6>] ? 
sysfs_new_dirent+0x46/0xe0
Dec 19 14:38:50 tyleet kernel: [  240.297526]  [<c111c553>] ? 
sysfs_addrm_finish+0x13/0xb0
Dec 19 14:38:50 tyleet kernel: [  240.297536]  [<c111c653>] ? 
create_dir+0x63/0xa0
Dec 19 14:38:50 tyleet kernel: [  240.297546]  [<c13026a5>] ? 
schedule_preempt_disabled+0x5/0x10
Dec 19 14:38:50 tyleet kernel: [  240.297556]  [<c13035bb>] ? 
__mutex_lock_slowpath+0x4b/0x7a
Dec 19 14:38:50 tyleet kernel: [  240.297567]  [<c1215e30>] ? 
driver_probe_device+0x1f0/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297577]  [<c1303123>] ? 
mutex_lock+0x13/0x15
Dec 19 14:38:50 tyleet kernel: [  240.297586]  [<c1215e76>] ? 
__driver_attach+0x46/0x80
Dec 19 14:38:50 tyleet kernel: [  240.297598]  [<c1214698>] ? 
bus_for_each_dev+0x38/0x70
Dec 19 14:38:50 tyleet kernel: [  240.297608]  [<c1215876>] ? 
driver_attach+0x16/0x20
Dec 19 14:38:50 tyleet kernel: [  240.297617]  [<c1215e30>] ? 
driver_probe_device+0x1f0/0x1f0
Dec 19 14:38:50 tyleet kernel: [  240.297626]  [<c1215521>] ? 
bus_add_driver+0xe1/0x1e0
Dec 19 14:38:50 tyleet kernel: [  240.297638]  [<c1216401>] ? 
driver_register+0x51/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297649]  [<f8070000>] ? 0xf806ffff
Dec 19 14:38:50 tyleet kernel: [  240.297659]  [<c1000462>] ? 
do_one_initcall+0xe2/0x130
Dec 19 14:38:50 tyleet kernel: [  240.297668]  [<c1303118>] ? 
mutex_lock+0x8/0x15
Dec 19 14:38:50 tyleet kernel: [  240.297678]  [<c1093a55>] ? 
jump_label_module_notify+0x155/0x1a0
Dec 19 14:38:50 tyleet kernel: [  240.297689]  [<c104e890>] ? 
notifier_call_chain+0x40/0x60
Dec 19 14:38:50 tyleet kernel: [  240.297702]  [<c104eadb>] ? 
__blocking_notifier_call_chain+0x4b/0x70
Dec 19 14:38:50 tyleet kernel: [  240.297713]  [<c107c988>] ? 
load_module+0x1a18/0x2160
Dec 19 14:38:50 tyleet kernel: [  240.297730]  [<c102d920>] ? 
vmalloc_sync_all+0xd0/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297741]  [<c107d161>] ? 
SyS_init_module+0x91/0xd0
Dec 19 14:38:50 tyleet kernel: [  240.297761]  [<c130489e>] ? 
sysenter_do_call+0x12/0x26

Greetings,
     Thomas