kernel-packages team mailing list archive

[Bug Watch Updater <1330785@xxxxxxxxxxxxxxxxxx>]

Launchpad has imported 42 comments from the remote bug at
https://bugs.freedesktop.org/show_bug.cgi?id=75761.

If you reply to an imported comment from within Launchpad, your comment
will be sent to the remote bug automatically. Read more about
Launchpad's inter-bugtracker facilities at
https://help.launchpad.net/InterBugTracking.

------------------------------------------------------------------------
On 2014-03-04T15:57:32+00:00 Soundx94 wrote:

Created attachment 95103
The log of weston after quiting.

Hi.

I'm trying to start weston with weston-launch in archLinux with the latest packages from the official repositories.
I've got an Nvidia card with Nouveau and nouveau-fw from the arch user repository and the latest mesa packages and KMS enabled.
Weston-launch seems to start correctly but the weston interface doesn't show up, the output is only a black screen. I can quit weston using Ctrl Alt backspace but nothing else.

When i'm trying to start just weston from an X session everything works
fine but weston-launch is failing somehow.

Weston log attached.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/0

------------------------------------------------------------------------
On 2014-03-04T18:01:23+00:00 Ppaalanen wrote:

Could you check if weston-simple-shm gets anything to screen?

You can try it first when you run weston under X to see what it is
supposed to show, and then when using weston-launch. VT switching should
work, but if it does not, you might need to use ssh for access from
remote or use a delay to start weston-simple-shm in another VT.

If weston-simple-shm seems to run, but still nothing on screen, then we
should start suspecting an issue with Nouveau.

Did you check the kernel log for Nouveau errors?

You are not trying to use weston-launch from an X terminal, right?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/1

------------------------------------------------------------------------
On 2014-03-05T08:20:05+00:00 Soundx94 wrote:

So I tried running weston-simple-shm under weston in an X session and it worked fine. (Guessing this multi-colored circle stuff is expected to show up)
After quiting the X session and opening another VT with weston-launch in the first and weston-simple-shm in the second the first VT was still black and there is nothing nasty in the log.
Of course i'm NOT trying to run weston-launch from X.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/2

------------------------------------------------------------------------
On 2014-03-05T09:02:56+00:00 Ppaalanen wrote:

Ok, it sounds like it would have something to do with Nouveau then. I
vaguely recall a few people having such problems with Nouveau in the
past. Maybe look into Nouveau's bugzilla, if there are any reports about
Weston?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/3

------------------------------------------------------------------------
On 2014-03-05T13:44:24+00:00 Soundx94 wrote:

Okai, thanks for your help :)
If anything turns up or a solution is found i'll post it here.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/4

------------------------------------------------------------------------
On 2014-04-04T00:45:04+00:00 Lubosz Sarnecki wrote:

I can confirm this bug. Also Arch Linux.

I tried downgrading mesa to 10.0.3, but it did not help, as described in
this post http://www.maui-project.org/news/2014/04/02/how-to-fix-mesa-
on-arch-linux/

Under X I get following nouveau error (not in tty)

libEGL debug: driver does not expose __driDriverGetExtensions_nouveau():
/usr/lib/xorg/modules/dri/nouveau_dri.so: undefined symbol:
__driDriverGetExtensions_nouveau

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/5

------------------------------------------------------------------------
On 2014-04-04T11:17:54+00:00 Zachcook1991 wrote:

Also can confirm, running Arch with nouveau, on linux 3.14.

I just installed linux-lts (currently at version 3.10.x) and it runs
weston fine on a tty, so this is clearly a nouveau kernel issue from a
fairly recent change.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/6

------------------------------------------------------------------------
On 2014-04-04T12:25:43+00:00 Ppaalanen wrote:

Alright, thanks Zach. Anything relevant in kernel logs? I assume linux-
lts refers just to the kernel?

Would anyone be up for bisecting the kernel? You can probably limit the
bisection to the drivers/gpu/drm/nouveau directory.

We could reassign this bug to Nouveau, but I think they would just ask
for a bisection as the first thing, since this is apparently a
regression.

Lubosz, the libEGL message is harmless.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/7

------------------------------------------------------------------------
On 2014-04-04T16:36:52+00:00 Lubosz Sarnecki wrote:

Kernel 3.10 also works for me. Tested on NVC8 and NV50. I will bisect
the kernel.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/8

------------------------------------------------------------------------
On 2014-04-07T23:08:17+00:00 Kristian Hoegsberg wrote:

Thanks for investigating.  Closing as NOTOURBUG for now, please reopen
if it turns out to be a weston issues after all.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/9

------------------------------------------------------------------------
On 2014-04-09T09:29:27+00:00 Ppaalanen wrote:

Trying to move this to Nouveau, BZ is being difficult...

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/10

------------------------------------------------------------------------
On 2014-04-09T09:30:14+00:00 Ppaalanen wrote:

Reopening as Nouveau bug...

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/11

------------------------------------------------------------------------
On 2014-04-09T09:32:13+00:00 Ppaalanen wrote:

Setting status to NEW, since this is a new Nouveau bug report, moved from Weston.
Said to be a kernel regression after 3.10.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/12

------------------------------------------------------------------------
On 2014-04-10T22:04:39+00:00 Lubosz Sarnecki wrote:

My bisection process so far is pretty frustrating, 
since the majority of the commits between 3.12 and 3.13 do not boot. 
I get corrupted output before being able to login. 

The screen looks like so:

http://i.imgur.com/C517qpP.jpg

My current progress:

# v3.12 good
# 0fef9d8a59abcd699761cb054b6c37a2bea9e31a  skip / won't boot
# 48ae0b355f21533145133002854de89a0537408d  skip / won't boot
# c17f5bb529221c7f4c0736e69ceb614da0df2838  bad
# 8df1d0c07f18bd84ea7d8c7bc2cff45ba2b09680  skip / won't boot
# 16c4f227ffc556a4851518092e2b5979da1280c1  skip / won't boot
# 5fa7543041cbc2d3139e8d2178df61a33ac3f9ac  skip / won't boot
# 6d8d163132d7df6ca701efcde7832046ecb2f040  skip / won't boot
# 98706ea99f2da8afdac69686de4ff982aca6a5c7  skip / won't boot
# v3.13 bad
# v3.14 bad

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/13

------------------------------------------------------------------------
On 2014-04-10T22:07:12+00:00 Lubosz Sarnecki wrote:

I am only bisecting the nouveau directory, like so:

git bisect start v3.14 v3.10 -- drivers/gpu/drm/nouveau

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/14

------------------------------------------------------------------------
On 2014-04-10T22:10:53+00:00 Ilia Mirkin wrote:

(In reply to comment #13)
> My bisection process so far is pretty frustrating, 
> since the majority of the commits between 3.12 and 3.13 do not boot. 
> I get corrupted output before being able to login. 

What HW are you using?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/15

------------------------------------------------------------------------
On 2014-04-10T22:14:42+00:00 Lubosz Sarnecki wrote:

Chipset: GF110 (NVC8)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/16

------------------------------------------------------------------------
On 2014-04-10T22:16:48+00:00 Ilia Mirkin wrote:

(In reply to comment #16)
> Chipset: GF110 (NVC8)

There are known issues with NVC8 that go away with blob pgraph fw,
perhaps worth trying with that. (See bug #54437.)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/17

------------------------------------------------------------------------
On 2014-04-10T23:39:03+00:00 Lubosz Sarnecki wrote:

I was able to boot all commits with following boot option:
nouveau.config=NvMSI=0

Thanks to xexaxo on the IRC for pointing out this option.


f074d733866628973eca0ddb0c534ef4561da9e0 is the first bad commit
commit f074d733866628973eca0ddb0c534ef4561da9e0
Author: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxx>
Date:   Wed Nov 20 15:14:31 2013 +1000

    drm/nouveau/kms: send timestamp data for correct head in flip completion events
    
    Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>

:040000 040000 99b978c435e8bb3e7bd91e30daf953940dcfe99c
dcff6c807e51e53d4de0064678c46bfd68e0a1ca M      drivers


Canonical broke Weston for me ;)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/18

------------------------------------------------------------------------
On 2014-04-10T23:52:21+00:00 Lubosz Sarnecki wrote:

Reverting the patch on current Linux master
(4a4389abdd9822fdf3cc2ac6ed87eb811fd43acc) fixes the issue for me.

Apperently s->crtc needs to be hardcoded to -1 for the screen not to
stay black when launching weston.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/19

------------------------------------------------------------------------
On 2014-04-17T11:54:03+00:00 Soundx94 wrote:

Thanks for bisecting the kernel. Reverting that patch on the latest kernel also fixes the issue for me.
(Using NVE6: GTX 660)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/20

------------------------------------------------------------------------
On 2014-04-17T12:33:26+00:00 Ppaalanen wrote:

(In reply to comment #20)
> Thanks for bisecting the kernel. Reverting that patch on the latest kernel
> also fixes the issue for me.
> (Using NVE6: GTX 660)

Hey, wait! Why did you close this bug?

Has upstream merged a fix, or did this problem never occur on upstream
(hard to imagine)?

It's not enough that you personally find a hack that fixes it for you
alone, we want it fixed for everybody.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/21

------------------------------------------------------------------------
On 2014-04-17T12:37:21+00:00 Soundx94 wrote:

I thought WORKSFORME is the proper status because it works for me at the
moment with this modification and it can get merged into upstream. Sorry
if i misunderstood the status label, do you want me to reopen it ?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/22

------------------------------------------------------------------------
On 2014-04-17T12:42:39+00:00 Ppaalanen wrote:

(In reply to comment #22)
> I thought WORKSFORME is the proper status because it works for me at the
> moment with this modification and it can get merged into upstream. Sorry if
> i misunderstood the status label, do you want me to reopen it ?

WORKSFORME means, that maintainers or developers cannot reproduce the
bug at all, and cannot find anything wrong.

I reopened this for you.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/23

------------------------------------------------------------------------
On 2014-05-28T18:27:46+00:00 Lubosz Sarnecki wrote:

Since Weston and Wayland 1.5.0 were released today, I wanted to ask
about the status of this bug.

Does the patch which causes the regression have enough legitimacy to
stay and break Weston?

Does someone understand the problem on a large scale?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/24

------------------------------------------------------------------------
On 2014-05-28T18:57:37+00:00 Ilia Mirkin wrote:

(In reply to comment #24)
> Since Weston and Wayland 1.5.0 were released today, I wanted to ask about
> the status of this bug.
> 
> Does the patch which causes the regression have enough legitimacy to stay
> and break Weston?

It seems like a pretty correct fix, at first blush. And was necessary
for something else, IIRC.

> 
> Does someone understand the problem on a large scale?

It'll take someone with KMS API and Wayland experience to work out
what's going on. Probably would have to get a Wayland developer involved
to figure this one out.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/25

------------------------------------------------------------------------
On 2014-05-30T09:18:36+00:00 Ppaalanen wrote:

What did the -1 as crtc mean?

I'm not sure how this is weston-specific, though. Weston programs a
pageflip on a certain crtc, and then relies on that particular crtc to
send back a pageflip event as requested.

So if that's the culprit, is Nouveau on some particular hardware sending
back pageflip events on the wrong crtc? Or maybe mixing up crtcs so that
no event gets sent?

This would be easy to test by adding a weston_log("got pageflip
event\n") to src/compositor-drm.c:745, in function page_flip_handler(),
and another in line 723 in vblank_handler(). The vblank_handler should
be unused atm. I think.

If Weston never gets the pageflip event, its repaint loop would be
stuck, which would explain the symptoms. A side effect would be that
clients would never get frame callbacks, which means that e.g. weston-
simple-shm would not be consuming any CPU. Normally it should take at
least few percent of one core. Otherwise everything would seem to just
work, since Weston does not hang but only not repaint.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/26

------------------------------------------------------------------------
On 2014-05-31T03:41:53+00:00 Nerdopolis1 wrote:

I pulled out my old Dell desktop with a Pentium 4 processor, and AGB
Nvidia card (NV36), and it does the same thing. Mark45 on Phoronix said
this issue affected all 3 of his Nvidia cards when he tried to use my
Wayland Live CD.

I added the "got pageflip event" lines as suggested, and it seems that
they appear multiple times in the log, and seem to keep going until I
tty switch, but the screen is still black. Using a vanilla Ubuntu
kernel, and passing nouveau.config=NvMSI=0 did not work for me, or for
Mark45 on any of his Nvidia cards.

Weston-desktop-shell starts fine, and I also tried weston-simple-shm,
which did not appear, but it did run.

It can't be a mesa issue, as Weston is using pixman here in this case...

I wish I had tested this sooner, but I wasn't sure if my results on the
older desktop would reflect on newer Nvidia hardware.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/27

------------------------------------------------------------------------
On 2014-05-31T08:23:03+00:00 Ppaalanen wrote:

I wonder if there are two different bugs in play here.

If you do get the vblank events right, like it sounds that Nerdopolis
does indeed get, then does reverting the blamed nouveau kernel patch
make any difference? I would be surprised if it does make a difference.

This other bug would be, that when Weston changes the video mode, it
does not call drmModeCrtcSetGamma. IIRC Michel Dänzer told me, that not
calling that may lead to black output, if the color translations tables
are all zero due not being explicitly set. So the main question here is,
does Weston change the video mode, or does it use the mode that is
already set for fbcon?

Weston code base already has a call to drmModeCrtcSetGamma(), but it is
used only for color managed outputs I think. Yet, it is an example of
how to call it, so if someone having this problem could test that, it
would be very useful. If missing this call is indeed the problem, I
think it should be a new Weston bug report, as the Nouveau patch blamed
here should not make a difference AFAIU.

One more note: if you test reverting the blamed Nouveau patch, make sure
your *both* kernels with and without are built by you and launched the
same way, to make sure that the fbcon video mode is really the same on
both. If the fbcon video mode is different, then that could mask the
drmModeCrtcSetGamma issue.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/28

------------------------------------------------------------------------
On 2014-05-31T08:32:23+00:00 Ppaalanen wrote:

Hmm, a third remote possibility came to mind. If the timestamp delivered
with the DRM pageflip event does not advance, I suppose Weston's fade-in
animation might not advance either and therefore it never fades in.
However this is hard for me to believe, as I think it would have caused
problems with Xorg, too... wouldn't it?

Or maybe Xorg is only looking at the vblank counters, and you'd actually
need a program using GLX_OML_sync_control to even see the timestamps?

One could check the timestamps by:
weston_log("%s: time %u.%06u frame %u\n", __func__, sec, usec, frame);
in compositor-drm.c page_flip_handler() function.

Mm, I'd like to see a weston log with that when you have the black
screen problem.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/29

------------------------------------------------------------------------
On 2014-05-31T11:49:32+00:00 Nerdopolis1 wrote:

The only interesting thing that I can find in the dmesg logs is this:


[    1.509268] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.509269] [drm] No driver support for vblank timestamp query.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/30

------------------------------------------------------------------------
On 2014-05-31T12:29:14+00:00 Nerdopolis1 wrote:

Created attachment 100199
weston log with pixman

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/31

------------------------------------------------------------------------
On 2014-06-01T10:15:47+00:00 Ppaalanen wrote:

(In reply to comment #31)
> Created attachment 100199 [details]
> weston log with pixman

Something is seriously wrong here:
[09:58:29.402] queueing pageflip failed: Permission denied

But I see you have another weston session afterwards, which seems to run, but:
[12:26:36.371] page_flip_handler: time 0.000000 frame 603
[12:26:36.371] got pageflip event
[12:26:36.388] page_flip_handler: time 0.000000 frame 603
[12:26:36.388] got pageflip event
[12:26:36.404] page_flip_handler: time 0.000000 frame 603
[12:26:36.404] got pageflip event
[12:26:36.421] page_flip_handler: time 0.000000 frame 603
[12:26:36.421] got pageflip event
[12:26:36.437] page_flip_handler: time 0.000000 frame 603
[12:26:36.438] got pageflip event
[12:26:36.454] page_flip_handler: time 0.000000 frame 603

That means that the kernel DRM driver does not provide timestamps and it
does not even advance the vblank counter(?) if I understood right.

So at least for you, the problem is that the kernel DRM does not report
proper pageflip timestamps. I would consider this as a kernel driver
bug, but if the kernel developers insist, I suppose we could also hack
around it in Weston by providing fake timestamps, disabling the
Presentation extension (somewhat similar X11 Present, not yet merged)
and yelling loudly. But I'd rather the driver got fixed.

As far as I see, bad timestamps are enough to make Weston stay black
(fade-in animation not advancing), yet appear to work just fine. So at
least we (Weston devs) should detect when the kernel driver is faulty,
and abort Weston.

Weston, and also the intention in Wayland, is to rely on the proper
pageflip timestamps from the kernel for timing... well, everything
visual, so we really would like it to work.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/32

------------------------------------------------------------------------
On 2014-06-01T10:29:04+00:00 Ppaalanen wrote:

I filed bug #79502 for adding the detection to Weston.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/33

------------------------------------------------------------------------
On 2014-06-01T12:59:00+00:00 Nerdopolis1 wrote:

Just an FYI, I think the

[09:58:29.402] queueing pageflip failed: Permission denied

came from when I killed the previous Weston session, to have the
waylandloginmanager reload Weston after I recompiled it with the diag
lines on my live session. I was in another TTY

That was the only time I ever seen that happen so far

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/34

------------------------------------------------------------------------
On 2014-06-10T01:28:27+00:00 Ilia Mirkin wrote:

A few pageflip-related commits landed in the repo:

http://cgit.freedesktop.org/~darktama/nouveau/

http://cgit.freedesktop.org/~darktama/nouveau/commit/?id=ff527544b0048d41a56097a66ff954fb9b0a2c75

Seems related to what was going on here. Give it a shot... (you'll need
to build it against the latest drm-next tree from
http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-next). Or try to
apply the patches to whatever kernel tree you're on -- should probably
work.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/35

------------------------------------------------------------------------
On 2014-06-14T22:24:59+00:00 Nerdopolis1 wrote:

I'm trying to compile the module... it seems that it's gone from the log
now???

How do I disable werror too?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/36

------------------------------------------------------------------------
On 2014-06-14T23:45:08+00:00 Nerdopolis1 wrote:

I found out how to turn off werror, but I guess I need to know what
patches I need to apply... Is that the only commit that I need to try
the fix?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/37

------------------------------------------------------------------------
On 2014-06-15T00:03:11+00:00 Ilia Mirkin wrote:

All the patches are now in drm-next, just use that.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/38

------------------------------------------------------------------------
On 2014-06-15T00:16:56+00:00 Nerdopolis1 wrote:

I would at least like to try to just try to apply them against the 3.13
nouveau module, instead of trying to rebuild the whole kernel first? So
is that the only patch I would need?

I'm still on 3.13 (which is also affected), as I have been doing all of
my testing on the Weston side of things...

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/39

------------------------------------------------------------------------
On 2014-06-15T18:48:58+00:00 Ilia Mirkin wrote:

(In reply to comment #39)
> I would at least like to try to just try to apply them against the 3.13
> nouveau module, instead of trying to rebuild the whole kernel first? So is
> that the only patch I would need?
> 
> I'm still on 3.13 (which is also affected), as I have been doing all of my
> testing on the Weston side of things...

Pretty sure that's the only patch. There were 2 other patches, but they
only matter for pre-nv50 hardware, which I assume you're not using
(GeForce 7 and earlier).

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/40

------------------------------------------------------------------------
On 2014-06-17T00:03:53+00:00 Nerdopolis1 wrote:

I found the second patch too, and I applied that as well. It works now,
even after I applied them to 3.13, and built just the Nouveau module.

I have an older Nvidia card, I think it's NV36.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1330785/comments/41


** Changed in: linux
       Status: Unknown => Confirmed

** Changed in: linux
   Importance: Unknown => Medium

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1330785

Title:
  Weston on Nouveau displays black screen on Nouveau due to page flip
  issues

Status in The Linux Kernel:
  Confirmed
Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  Hi.

  On Ubuntu 13.04, it seems that Weston displays a black screen, and the
  screen stays black, due to page flipping issues in the Nouveau driver
  as reported here https://bugs.freedesktop.org/show_bug.cgi?id=75761

  It seems that these two patches do apply to 3.13, and fix the pageflip
  issues, and it worked on my NV36 card: (One file I had to slightly
  alter myself)

  http://cgit.freedesktop.org/~airlied...751f25ebe60f28
  http://cgit.freedesktop.org/~airlied...5b438629d6858a

  I haven't been able to test on newer Nvidia cards because I don't have
  any, but I might be hearing back from others that do have newer caard.

  Is it possible that these can be officially backported  in Ubuntu
  13.04?

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1330785/+subscriptions