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

[Jani Nikula]

On Tue, 14 Mar 2017, 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 .

That would be

commit f2a0409a08502d64fbe3990354dff5902b08d2fb
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Sep 21 14:51:08 2016 +0100

    drm/i915/execlists: Reset RING registers upon resume
    
    commit bafb2f7d4755bf1571bd5e9a03b97f3fc4fe69ae upstream.

in v4.9.9 not just a 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 .

Please file a bug over at [1], with the information added to the bug.

Also mention if v4.10 works for you; that's where the commit was
backported to v4.9.9 from.

BR,
Jani.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel


-- 
Jani Nikula, Intel Open Source Technology Center