Re: No display after resume in r196086

2009/8/13 Robert Noland <rnoland_at_freebsd.org>:
> On Wed, 2009-08-12 at 20:21 -0400, Damian Gerow wrote:
>> Some time between r195828 and r196086, resuming from an S3 suspend seems to
>> have broken for me.
>>
>> When resuming in text mode, the system locks up completely before the
>> screen comes back on.  Of course, resuming from text mode has never worked,
>> so this isn't much of a concern.
>>
>> When resuming from graphics mode, the screen is restored, but fails to
>> update beyond restoring the initial display.  The keyboard responds (caps
>> lock light turns on, changing the console results in an error beep), but
>> that's about it.  Ctrl+alt+delete does cleanly reboot the system at this
>> point, and after reboot, I can see the system did actually come back
>> cleanly.
>>
>> The system is a Lenovo X200, running an amd64 install of r196086 (standard
>> GENERIC kernel)  The graphics chipset is an Intel X4500MHD.
>
> Looking at the change log, I suspect the newbus locking code... But that
> is just a stab in the dark.  There were not any changes to drm, which is
> responsible for saving/restoring state when it is loaded.

Damnian,
why don't you directly try the revision immediately before newbus
locking (so immediately prior to r196037) and try to verify it still
works.
I'm aware of at least one possible deadlock source but it should not
happen while suspend/resume. However, I'm preparing an errata patch
for newbus locking.
If you verify newbus locking is the real culprit and that my further
patch doesn't fix your problem we can try to hammer it down further.

Attilio


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