[Intel-gfx] 2.6.37 intel driver crash on hibernate

[Chris Wilson]

On Wed, 9 Feb 2011 00:27:52 +0000, Pedro Ribeiro <pedrib at gmail.com> wrote:
> Hi,
> 
> I've been having unreliable operation when hibernating ever since 2.6.37-rc5
> (the first 2.6.37 I tried).
> With 2.6.36 I never had a problem.

Wrong, you just never saw it.

commit 9334ef755f060e251f3f395caeda1a58b6834ea3
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Fri Jan 28 11:53:03 2011 +0000

    drm: Don't switch fb when disabling an output
    
    In drm_crtc_helper_set_config, we call drm_crtc_helper_set_mode which
    may return early and do no operation if the crtc is to be disabled. In
    this case we merrily swap to the new fb, discarding the old_fb believing
    that it has been cleaned up. However, due to the early return, the
    old_fb was not presented to the backend for correct reaping, and nor was
    the new one - which is about to be reaped via the
    drm_helper_disable_unused_functions(), leading to incorrect refcounting
    of the pinned objects.
    
    Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=27722
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29857
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29230
    Tested-by: Takashi Iwai <tiwai at suse.de>
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

-- 
Chris Wilson, Intel Open Source Technology Centre