linux-kernel - Re: linux-next: Tree for Aug 21 [ screen corruption in graphical mode ]

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Date:	Thu, 22 Aug 2013 13:13:26 +0200
From:	Sedat Dilek <sedat.dilek@...il.com>
To:	Sedat Dilek <sedat.dilek@...il.com>,
	Chris Wilson <chris@...is-wilson.co.uk>,
	linux-next <linux-next@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	intel-gfx <intel-gfx@...ts.freedesktop.org>,
	Stephen Rothwell <sfr@...b.auug.org.au>
Cc:	Daniel Vetter <daniel.vetter@...ll.ch>,
	"s.dilek" <s.dilek@...erlin.de>
Subject: Re: linux-next: Tree for Aug 21 [ screen corruption in graphical mode ]

On Thu, Aug 22, 2013 at 9:24 AM, Daniel Vetter <daniel@...ll.ch> wrote:
> On Thu, Aug 22, 2013 at 08:32:47AM +0200, Sedat Dilek wrote:
>> It's independent of the applied patch.
>> My problem goes away with SNA but still exists with UXA.
>>
>> As said in my previous analysis... switching back to Ubuntu's graphics
>> did not show the symptoms, too.
>>
>> It's interesting to see, it is a problem of the intel-ddx.
>
> Nope, it's just that uxa and sna have completely different buffer object
> usage patterns. Not the first time only one of them hits an issue ...
>
>> Anyway, SNA seems here to be approx. 20% faster in gtkperf-0.40, so I
>> will use it.
>>
>> I am open and willing to test any patches you will provide.
>> Please, let me know.
>
> Found a new bugger, please test the below patch.
>
> Thanks, Daniel
> ---
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index ef92c69..e0bff07 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2616,6 +2616,9 @@ int i915_vma_unbind(struct i915_vma *vma)
>         drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
>         int ret;
>
> +       /* For now we only ever use 1 vma per object */
> +       WARN_ON(!list_is_singular(&obj->vma_list));
> +
>         if (list_empty(&vma->vma_link))
>                 return 0;
>
> @@ -2661,7 +2664,9 @@ int i915_vma_unbind(struct i915_vma *vma)
>         drm_mm_remove_node(&vma->node);
>
>  destroy:
> -       i915_gem_vma_destroy(vma);
> +       /* Keep the vma as a placeholder in the execbuffer reservation lists */
> +       if (!list_empty(&vma->exec_list))
> +               i915_gem_vma_destroy(vma);
>
>         /* Since the unbound list is global, only move to that list if
>          * no more VMAs exist.
> @@ -4171,10 +4176,6 @@ void i915_gem_vma_destroy(struct i915_vma *vma)
>         WARN_ON(vma->node.allocated);
>         list_del(&vma->vma_link);
>
> -       /* Keep the vma as a placeholder in the execbuffer reservation lists */
> -       if (!list_empty(&vma->exec_list))
> -               return;
> -
>         kfree(vma);
>  }
>

dmesg (a lot of traces) and kernel-config attached.

UXA causes still screen corruption.

$ egrep -i 'uxa|sna|accelmethod' /var/log/Xorg.0.log
[   118.951] (**) intel(0): Option "AccelMethod" "uxa"
[   118.960] (II) UXA(0): Driver registered support for the following
operations:

- Sedat -

Is "drm/i915: More vma fixups around unbind/destroy" the nearly same fix?

[1] https://patchwork.kernel.org/patch/2848146/

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