Force buffer re-allocation when the backing display changes

Force buffer re-allocation when the backing display changes

When the user changes the primary display and both displays have the
same resolution, the buffers are never re-allocated. It is then possible
to encounter the following scenario:

Surface 1 scans out on display A and surface 2 scans out on display B.
When surface 1 moves to display B and surface 2 to display A there is no
guarantee that either surface will force re-draws. If, say, surface 1
starts page flipping it is possible that it would start re-using the
buffer currently shown on display A which could cause the GPU process to
wait for display A to release the buffer. At this point the GPU main
thread is blocked waiting without a possibility to progress since
surface 2 cannot use the GPU to update. Eventually the watchdog kills
the GPU process which causes the surfaces to be reallocated and progress
to continue.

BUG=511446
Committed: https://crrev.com/5bfd1d7ea19dae7cca921afa01cb0913d99514c0
Cr-Commit-Position: refs/heads/master@{#347933}

[dnicoara, 2015-09-08 21:03:32]

dnicoara@chromium.org changed reviewers:
+ alexst@chromium.org

[dnicoara, 2015-09-08 21:03:32]

PTAL

[alexst (slow to review), 2015-09-08 21:12:53]

lgtm

https://codereview.chromium.org/1334483002/diff/1/ui/ozone/platform/drm/gpu/d...
File ui/ozone/platform/drm/gpu/drm_surface.cc (right):

https://codereview.chromium.org/1334483002/diff/1/ui/ozone/platform/drm/gpu/d...
ui/ozone/platform/drm/gpu/drm_surface.cc:102: pending_pageflip_ = true;
Please make a quick note that this is a re-entrance issue.

[dnicoara, 2015-09-09 14:09:52]

https://codereview.chromium.org/1334483002/diff/1/ui/ozone/platform/drm/gpu/d...
File ui/ozone/platform/drm/gpu/drm_surface.cc (right):

https://codereview.chromium.org/1334483002/diff/1/ui/ozone/platform/drm/gpu/d...
ui/ozone/platform/drm/gpu/drm_surface.cc:102: pending_pageflip_ = true;
On 2015/09/08 21:12:53, alexst wrote:
> Please make a quick note that this is a re-entrance issue.

Done.

[dnicoara, 2015-09-09 14:10:00]

The CQ bit was checked by dnicoara@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-09 14:10:07]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334483002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334483002/20001

[commit-bot: I haz the power, 2015-09-09 14:55:47]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-09 14:55:47]

Dry run: This issue passed the CQ dry run.

[dnicoara, 2015-09-09 15:08:24]

The CQ bit was checked by dnicoara@chromium.org

[dnicoara, 2015-09-09 15:08:25]

The patchset sent to the CQ was uploaded after l-g-t-m from alexst@chromium.org
Link to the patchset: https://codereview.chromium.org/1334483002/#ps20001
(title: "add comment")

[commit-bot: I haz the power, 2015-09-09 15:08:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1334483002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1334483002/20001

[commit-bot: I haz the power, 2015-09-09 15:15:07]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-09 15:15:46]

Patchset 2 (id:??) landed as
https://crrev.com/5bfd1d7ea19dae7cca921afa01cb0913d99514c0
Cr-Commit-Position: refs/heads/master@{#347933}