[Intel-gfx] Potential BUG in drm/i915/execlists: Reset RING registers upon resume

[Eric Blau]

That's funny. I have a MacBook Pro 12,1 from late 2015. Hibernate
failed for me in 4.9.6 through 4.9.8 (possibly earlier as well, I do
no recall) without the patch. The patch you reference fixed my problem
and apparently many others based on the bug reports:

https://bugs.freedesktop.org/show_bug.cgi?id=96526

I applied the patch myself in 4.9.6 through 4.9.8 and hibernate works
for me. I have run vanilla 4.9.9 and 4.10.1 and in both hibernate
works.

Regards,
Eric

On Mon, Mar 13, 2017 at 6:23 PM, Damian Dominik Martinez Dreyer
<damian at mailbox.org> wrote:
> I am writing regarding this kernel patch: https://git.kernel.org/pub/sc
> m/linux/kernel/git/stable/stable-queue.git/tree/releases/4.9.9/drm-
> i915-execlists-reset-ring-registers-upon-resume.patch .
>
> I have identified this by bisect to be the cause of a suspend and
> resume issue. Please see https://github.com/kxv/linux49.9 for the
> bisect history.
>
> After this change, a Laptop (HP Spectre x360) with Intel HD Graphics
> 520 will wake up from suspend to a blank screen.
>
> Please also see this thread on the manjaro linux forum: https://forum.m
> anjaro.org/t/linux-4-9-9-breaks-hibernation-4-9-8-works/17499 .
>
>
> Best regards
> Damian Dominik Martinez Dreyer