Re: [Intel-gfx] [git pull] drm fixes

From: Daniel Vetter
Date: Wed Mar 25 2015 - 04:52:46 EST


On Tue, Mar 24, 2015 at 12:10:28PM -0400, Josh Boyer wrote:
> On Tue, Mar 24, 2015 at 10:46 AM, Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx> wrote:
> > On Tue, Mar 24, 2015 at 10:34 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
> >> On Tue, Mar 24, 2015 at 10:22:30AM -0400, Josh Boyer wrote:
> >>> On Tue, Mar 24, 2015 at 9:57 AM, Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx> wrote:
> >>> > On Tue, Mar 24, 2015 at 9:40 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
> >>> >> On Tue, Mar 24, 2015 at 09:15:32AM -0400, Josh Boyer wrote:
> >>> >>> On Tue, Mar 24, 2015 at 3:32 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
> >>> >>> > On Mon, Mar 23, 2015 at 02:34:27PM -0400, Josh Boyer wrote:
> >>> >>> >> On Mon, Mar 23, 2015 at 11:33 AM, Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx> wrote:
> >>> >>> >>
> >>> >>> >> <snip>
> >>> >>> >>
> >>> >>> >> >> Xi Ruoyao (1):
> >>> >>> >> >> drm/i915: Ensure plane->state->fb stays in sync with plane->fb
> >>> >>> >>
> >>> >>> >> Turns out to be that commit.
> >>> >>> >>
> >>> >>> >> git bisect start 'drivers/gpu/drm/i915/'
> >>> >>> >> # good: [b314acaccd7e0d55314d96be4a33b5f50d0b3344] Merge branch
> >>> >>> >> 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
> >>> >>> >> git bisect good b314acaccd7e0d55314d96be4a33b5f50d0b3344
> >>> >>> >> # bad: [bc465aa9d045feb0e13b4a8f32cc33c1943f62d6] Linux 4.0-rc5
> >>> >>> >> git bisect bad bc465aa9d045feb0e13b4a8f32cc33c1943f62d6
> >>> >>> >> # bad: [319c1d420a0b62d9dbb88104afebaabc968cdbfa] drm/i915: Ensure
> >>> >>> >> plane->state->fb stays in sync with plane->fb
> >>> >>> >> git bisect bad 319c1d420a0b62d9dbb88104afebaabc968cdbfa
> >>> >>> >> # first bad commit: [319c1d420a0b62d9dbb88104afebaabc968cdbfa]
> >>> >>> >> drm/i915: Ensure plane->state->fb stays in sync with plane->fb
> >>> >>> >>
> >>> >>> >> Doing a straight revert on top of 4.0-rc5 makes things work again,
> >>> >>> >> albeit with the WARN_ON(obj->frontbuffer_bits) splat still being
> >>> >>> >> there.
> >>> >>> >
> >>> >>> > Can you please test the tip of drm-fixes:
> >>> >>> >
> >>> >>> > commit 8218c3f4df3bb1c637c17552405039a6dd3c1ee1
> >>> >>> > Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
> >>> >>> > Date: Fri Feb 27 12:58:13 2015 +0100
> >>> >>> >
> >>> >>> > drm: Fixup racy refcounting in plane_force_disable
> >>> >>> >
> >>> >>> > http://cgit.freedesktop.org/~airlied/linux/commit/?h=drm-fixes&id=8218c3f4df3bb1c637c17552405039a6dd3c1ee1
> >>> >>> >
> >>> >>> > Because fumble that patch didn't make it to drm-fixes a while ago and
> >>> >>> > instead landed in drm-next.
> >>> >>>
> >>> >>> That seems to have helped with totally different issues a macbook I
> >>> >>> have was seeing. However, it still doesn't fix the issue with the
> >>> >>> Celeron based NUC machine.
> >>> >>>
> >>> >>> I built a kernel based on Linus' latest tree as of this morning,
> >>> >>> without reverting 319c1d4 and adding the commit you pointed to. The
> >>> >>> NUC still won't boot without HDMI connected. With HDMI connected I
> >>> >>> still see the trace below. If I do the blacklist and then insmod
> >>> >>> dance with HDMI unplugged it shows the same spew I reported yesterday
> >>> >>> which starts with the same backtrace.
> >>> >>>
> >>> >>> I'll try building a kernel with 319c1d4 reverted + your patch. I
> >>> >>> suspect things will work fine with that combination because the two
> >>> >>> issues are unrelated.
> >>> >>
> >>> >> Can you please boot with drm.debug=0xff for the below case and grab
> >>> >> complete dmesg? There'll be a lot of crap in the logs, you might need to
> >>> >> blow up the logbuf size massively. But that log should contain everything
> >>> >> I need to figure out where that framebuffer we're blowing up on is going.
> >>> >
> >>> > I provided both with HDMI attached and without (via insmod). If you
> >>> > want them emailed directly let me know, but they were large.
> >>> >
> >>> > Boot with drm.debug=0xff and HDMI connected:
> >>> >
> >>> > https://jwboyer.fedorapeople.org/pub/drm-ff-dmesg.txt
> >>> >
> >>> > Boot with drm.debug=0xff without HDMI connected and i915 loaded via
> >>> > manual insmod after boot:
> >>> >
> >>> > https://jwboyer.fedorapeople.org/pub/drm-ff-no-hdmi-insmod.txt
> >>>
> >>> Here's one more from the macbook I mentioned. It's showing the same
> >>> kref.h splat:
> >>>
> >>> https://jwboyer.fedorapeople.org/pub/drm-ff-macbook.txt
> >>
> >> Ok there's at least one fixup for which we've failed to apply when porting
> >> the fb refcounting fix from -next. Can you please cherry-pick
> >>
> >> commit f55548b5af87ebfc586ca75748947f1c1b1a4a52
> >> Author: Damien Lespiau <damien.lespiau@xxxxxxxxx>
> >> Date: Thu Feb 5 18:30:20 2015 +0000
> >>
> >> drm/i915: Don't try to reference the fb in get_initial_plane_config()
> >>
> >> From linux-next?
> >
> > Yes, building now. Will let you know as soon as I test it on both machines.
>
> OK, with that commit applied I no longer get the kref.h splat and the
> NUC machine boots headless. I still see the backtrace below on both
> the NUC and the macbook. I have a copy of it with drm.debug=0xff from
> the NUC here:
>
> https://jwboyer.fedorapeople.org/pub/nuc-drm-debug-ff-with-fixes.txt
>
> Getting better at least :).

On top of what you currently have please also cherry-pick

commit fb9981aa675eb7b398849915364916fd98833cfa
Author: Damien Lespiau <damien.lespiau@xxxxxxxxx>
Date: Thu Feb 5 19:24:25 2015 +0000

drm/i915: Fix atomic state when reusing the firmware fb

from -next. Let's hope this terminates eventually ;-)

Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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