I've bisected back to this commit in the drm-intel-nightly branch 05a76d3d6ad1ee9f9814f88949cc9305fc165460 is the first bad commit commit 05a76d3d6ad1ee9f9814f88949cc9305fc165460 Author: Lyude <cpaul@redhat.com> Date: Wed Aug 17 15:55:57 2016 -0400 drm/i915/skl: Ensure pipes with changed wms get added to the state … If we're enabling a pipe, we'll need to modify the watermarks on all active planes. Since those planes won't be added to the state on their own, we need to add them ourselves. Signed-off-by: Lyude <cpaul@redhat.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Cc: stable@vger.kernel.org Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-6-git-send-email-cpaul@redhat.com The symptoms I'm seeing look like tearing at the top of the screen and it's especially noticeable in Chrome - reverting this commit makes the issue go away I'll attach the contents of /sys/kernel/debug/dri/0/i915_ddb_info for working and not-working when I have access to my machine again
Created attachment 126707 [details] i915_ddb_info.working
Created attachment 126708 [details] i915_ddb_info.notworking
They're exactly the same
It's strange, when I move the cursor I see different windows flickering through, so if I move it quickly I can see the other Chrome windows and the terminal and my desktop
I can reproduce this, and reverting the mentioned patch seems to fix the problem. For me, there's no easy recipe to reproduce it: you have to keep using the system, and it will happen at some point. Usually, when I'm browsing Firefox and the flicker happens, it kinda displays the desktop background instead of Firefox, which is really weird since Firefox is fullscreen.
Is there anything else I can do to help with this bug? Would a video help?
Created attachment 126839 [details] [review] Posisble fix Hi Can you please confirm this fixes the problem? Thanks, Paulo
Should that be applied after the revert, or without the problem patch being reverted?
(In reply to Mike Lothian from comment #8) > Should that be applied after the revert, or without the problem patch being > reverted? Without the revert.
Reference to Paulo's patch: https://patchwork.freedesktop.org/series/13095/
It seems to fix things for me on other kernels affected by this, but I'm not able to boot highly at the moment. I'll try again later
Hello Since I'm highly confident that this patch will fix the problem because I could reproduce it, and since you already gave some confirmation that the patch fixes the problem for you, I'll close this bug. In case you think the problem persists, please feel free to reopen the bug report. This patch was marked for inclusion on the stable series, so it should reach your distro at some point. Thanks for all the help. We really appreciate when bug reporters take the time to help with git bisect :). Paulo
Could I have full steps to reproduce this issue? I want to make sure we have a testcase that could reproduce it, if it's feasible.
Likely test failure based on patch, still working on a test to reproduce: 1. busy bo flip 2. cursor update, primary plane is added to state 3. vblank happens 4. old contents of new fb shown because of cursor update 5. render completes, new fb contents shown Testing can be done by adding some crc tests to ensure that this doesn't happen.
Test is upstream as flip-vs-cursor-busy-crc-legacy, it currently fails until the call to add_all_affected_planes is completely removed. :(
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.