New issue
Advanced search Search tips
Note: Color blocks (like or ) mean that a user may not be available. Tooltip shows the reason.

Issue 709153 link

Starred by 1 user

Issue metadata

Status: Archived
Owner:
Closed: Apr 2017
Cc:
EstimatedDays: ----
NextAction: ----
OS: Chrome
Pri: 2
Type: Bug

Blocking:
issue 701389



Sign in to add a comment

4K display gets removed then readded again when changing the resolution from 4K to 1920x1080 or lower

Project Member Reported by afakhry@chromium.org, Apr 6 2017

Issue description

While working on  Issue 701389 , I found that the display gets removed and readded in the middle of the configuration when changing the resolution from 4K to 1920x1080 or lower.

DrmDisplayHostManager::GpuHasUpdatedNativeDisplays() sees 2 displays, then 1 display, then 2 displays again.

There's a workaround this issue, by increasing the kConfigureDelayMs in the DisplayConfigurator from 500ms to 1000ms, but that doesn't really fix the real issue, and the problem might show up in other displays.
 
Further investigation shows the ui::GetAvailableDisplayControllerInfos() returns only 1 display in the middle as it sees only 1 available_connector: https://cs.chromium.org/chromium/src/ui/ozone/platform/drm/common/drm_util.cc?q=GetAvailableDisplayControllerInfos+package:%5Echromium$&l=236
All the drmModeConnector connectors have a connection of type DRM_MODE_DISCONNECTED and |count_modes| equals to 0 -- except the internal display -- when the 4K display gets removed in the middle of the configuration to change the resolution.
Is it specific to that particular TV? Some TVs "disconnect and reconnect" themselves to force the sink to re-configure everything. If that's the case, increasing the timeout is the best thing we can do.
Re#3: I don't know. This is the only 4K TV I have at the moment, unless you have another one I can test with.
Cc: dbehr@chromium.org
Can you test with Dominik's monitor? It's the only other one we have.
We tested with Dominik's monitor, and it doesn't disconnect itself while configuring. So we think that this issue is specific to the TV I was testing with.

marcheu and oshima think that it's fine in this case to increase the configuration delay.
Project Member

Comment 7 by bugdroid1@chromium.org, Apr 14 2017

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3c3a243f32630f91deb983549b74728fbf2adb61

commit 3c3a243f32630f91deb983549b74728fbf2adb61
Author: afakhry <afakhry@chromium.org>
Date: Fri Apr 14 00:16:48 2017

Increase delay to perform the configuration to 1 sec.

Give TVs that disconnect themselves when their resolution changes more
time to readd themselves before we surface that to the user as a display
disconnected event.

BUG= 709153 
TEST=manually

Review-Url: https://codereview.chromium.org/2809763002
Cr-Commit-Position: refs/heads/master@{#464620}

[modify] https://crrev.com/3c3a243f32630f91deb983549b74728fbf2adb61/ui/display/manager/chromeos/display_configurator.h

Status: Fixed (was: Assigned)

Comment 9 by dchan@google.com, May 30 2017

Labels: VerifyIn-60
Labels: VerifyIn-61

Comment 11 by dchan@chromium.org, Jan 22 2018

Status: Archived (was: Fixed)

Sign in to add a comment