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

From: Xi Ruoyao
Date: Wed Mar 25 2015 - 19:32:33 EST




å 03/26/2015 03:40 AM, Josh Boyer åé:
On Wed, Mar 25, 2015 at 01:37:41PM -0400, Josh Boyer wrote:
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.
OK, that helped on all my machines I have. No backtraces and they all
boot again as I would expect. For the record, here is what I have on
top of -rc5:

drm-Fixup-racy-refcounting-in-plane_force_disable.patch
drm-i915-Don-t-try-to-reference-the-fb-in-get_initia.patch

and this patch:

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 177714a9d778..778e7fa41c17 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2439,6 +2439,8 @@ 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;
+ intel_crtc->base.primary->crtc = &intel_crtc->base;
update_state_fb(intel_crtc->base.primary);
return;
}
@@ -2469,6 +2471,8 @@ 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;
+ intel_crtc->base.primary->crtc = &intel_crtc->base;
obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe);
break;
}

which is a mash-up of:

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

and

"drm/i915: Fixup legacy plane->crtc link for initial fb config"

which you just sent out.

I think that covers everything.

josh
I've got an HDMI device from the laboratory. I'll help to test the solution.

--
Xi Ruoyao
School of Aerospace Science and Technology
Xidian University, Xi'an, China

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