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

From: Josh Boyer
Date: Wed Mar 25 2015 - 13:38:40 EST


On Wed, Mar 25, 2015 at 1:17 PM, Daniel Vetter <daniel@xxxxxxxx> wrote:
> On Wed, Mar 25, 2015 at 12:42:46PM -0400, Josh Boyer wrote:
>> On Wed, Mar 25, 2015 at 11:53 AM, Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx> wrote:
>> > On Wed, Mar 25, 2015 at 11:50 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
>> >> On Wed, Mar 25, 2015 at 11:37:35AM -0400, Josh Boyer wrote:
>> >>> On Wed, Mar 25, 2015 at 10:00 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
>> >>> > On Wed, Mar 25, 2015 at 09:11:17AM -0400, Josh Boyer wrote:
>> >>> >> On Wed, Mar 25, 2015 at 4:54 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
>> >>> >> >> >> 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 ;-)
>> >>> >>
>> >>> >> Hm. That one doesn't apply cleanly. I think because it needs:
>> >>> >>
>> >>> >> From 2d14030b1a9d0e89cfdca6f16851e2eac8cb4de0 Mon Sep 17 00:00:00 2001
>> >>> >> From: Damien Lespiau <damien.lespiau@xxxxxxxxx>
>> >>> >> Date: Thu, 5 Feb 2015 17:22:18 +0000
>> >>> >> Subject: drm/i915: Store the initial framebuffer in initial_plane_config
>> >>> >>
>> >>> >> first. Do you want me to grab both, or should I try and figure out
>> >>> >> how to backport fb9981aa67 without it?
>> >>> >
>> >>> > Oops missed that. The active ingredient is setting crtc->primary->state->crtc like this:
>> >>> > -Daniel
>> >>> >
>> >>> >
>> >>> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> >>> > index 1c12262029fb..bfc14a6046ea 100644
>> >>> > --- a/drivers/gpu/drm/i915/intel_display.c
>> >>> > +++ b/drivers/gpu/drm/i915/intel_display.c
>> >>> > @@ -2439,6 +2439,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
>> >>> > return;
>> >>> >
>> >>> > if (intel_alloc_plane_obj(intel_crtc, plane_config)) {
>> >>> > + intel_crtc->base.primary->state->crtc = &intel_crtc->base;
>> >>> > update_state_fb(intel_crtc->base.primary);
>> >>> > return;
>> >>> > }
>> >>> > @@ -2469,6 +2470,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
>> >>> >
>> >>> > drm_framebuffer_reference(c->primary->fb);
>> >>> > intel_crtc->base.primary->fb = c->primary->fb;
>> >>> > + intel_crtc->base.primary->state->crtc = &intel_crtc->base;
>> >>> > obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe);
>> >>> > break;
>> >>> > }
>> >>>
>> >>> Hm. So I used your patch above. The macbook boots fine and all the
>> >>> oops/WARNS are gone except the audio one that was unrelated and
>> >>> present before all of this.
>> >>>
>> >>> However, the NUC is back to not booting without HDMI plugged in. I
>> >>> did the drm.debug=0xff+blacklist/insmod trick again and put the
>> >>> results up here:
>> >>>
>> >>> https://jwboyer.fedorapeople.org/pub/vetters.txt
>> >>>
>> >>> The frontbuffer splat is back now.
>> >>>
>> >>> I confirmed multiple times that the NUC boots fine with the kernel
>> >>> that doesn't include the above patch but has the other two included
>> >>> (albeit with the drm_atomic WARN still).
>> >>>
>> >>> Not sure what to make of this one.
>> >>
>> >> Yeah that fail looks like we're freeing an fb that's still in use.
>> >> Hilarity happens and since that happens under console_lock at boot-up your
>> >> machine dies.
>> >>
>> >> Does that machine die the same way in drm-intel-nightly/linux-next?
>> >
>> > I'll try that a bit later today. Out of sheer curiosity, I folded
>> > commit5ba76c41e55c (drm/i915: Put update_state_fb() next to the fb
>> > update) into the patch above and kicked off a build. The theory is
>> > that we're picking up a bunch of other changes right in that range of
>> > commits, why not try one more. I'll let you know if that fixes
>> > anything. Otherwise, I'll try building drm-intel-nightly and/or
>> > linux-next after that.
>>
>> The drm-intel-nightly build finished first. It boots without HDMI
>> plugged in, but it has pretty much the same splats as the previous
>> kernel. Confused. Full log here:
>>
>> https://jwboyer.fedorapeople.org/pub/intel-nightly.txt
>>
>> I don't have much hope for my other build.
>
> Yeah that's at least good news for the theory I've been cooking meanwhile.
> Can you try the below diff (on top of next/nightly)? For the current
> cherry-pick pile on top of 4.0-rc you'd need to prepend intel_crtc->base.
> to primary->...
>
> Thanks, Daniel
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index ceb2e61b4c91..cb508542c6ab 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2594,6 +2594,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
>
> primary->fb = &plane_config->fb->base;
> primary->state->crtc = &intel_crtc->base;
> + primary->crtc = &intel_crtc->base;
> update_state_fb(primary);
>
> return;
> @@ -2627,6 +2628,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
> drm_framebuffer_reference(c->primary->fb);
> primary->fb = c->primary->fb;
> primary->state->crtc = &intel_crtc->base;
> + primary->crtc = &intel_crtc->base;
> update_state_fb(intel_crtc->base.primary);
> obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe);
> break;

Hey, that seems to do the trick on the NUC machine. Boots without
HDMI connected and there are no backtraces. Nice!

Let me go and munge it around for a backport on top of -rc5 with the
rest of the pile and see if both the macbook and NUC machines work
then. Will be a bit for it to build.

josh
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