Re: [regression drm/noveau] suspend to ram -> BOOM: exception RIP: drm_calc_vbltimestamp_from_scanoutpos+335

From: Tobias Klausmann
Date: Wed Jul 12 2017 - 15:41:48 EST

On 7/12/17 7:19 PM, Mike Galbraith wrote:
On Wed, 2017-07-12 at 07:37 -0400, Ilia Mirkin wrote:
On Wed, Jul 12, 2017 at 7:25 AM, Mike Galbraith <efault@xxxxxx> wrote:
On Wed, 2017-07-12 at 11:55 +0200, Mike Galbraith wrote:
On Tue, 2017-07-11 at 14:22 -0400, Ilia Mirkin wrote:
Some display stuff did change for 4.13 for GM20x+ boards. If it's not
too much trouble, a bisect would be pretty useful.
Bisection seemingly went fine, but the result is odd.

e98c58e55f68f8785aebfab1f8c9a03d8de0afe1 is the first bad commit
But it really really is bad. Looking at gitk fork in the road leading
to it...

52d9d38c183b drm/sti:fix spelling mistake: "compoment" -> "component" - good
e4e818cc2d7c drm: make drm_panel.h self-contained - good
9cf8f5802f39 drm: add missing declaration to drm_blend.h - good

Before the git highway splits, all is well. The lane with commits
works fine at both ends, but e98c58e55f68 is busted. Merge arfifact?
Hmmm... that tree does not appear to have gotten a v4.12 backmerge at
any point. The last backmerge from Linus as far as I can tell was
v4.11-rc7. Could be an interaction with some out-of-tree change.
FWIW, checking out the fingered commit then..

git log --oneline 52d9d38c183b..e98c58e55f68|grep nouveau and reverting
the lot helped not at all.

Checking out 6b7781b42dc9 and reverting the fingered commit did. ÂGiven
the nouveau bits reverted are mostly the vblank changes, CC to Daniel,
maybe he'll know why both GTX 980 andÂGeForce 8600 GT get all upset.

Either I'm damn lucky, both of my nvidia equipped boxen going boom 100%
repeatably, or there are a lot of folks out there who haven't yet tried
suspend with our latest/greatest kernel. ÂI suspect the later.


I should have had a look at my inbox, would have save me a log of work bisecting. Yet i come to the same conclusion:

# first bad commit: [e98c58e55f68f8785aebfab1f8c9a03d8de0afe1] Merge tag 'drm-misc-next-2017-05-16' of git:// into drm-next

I suspect it is some vblank change as it shows up in every trace i have seen while bisecting, but that is just a wild guess...