On Mon, Oct 19, 2020 at 05:48:29PM +0200, Daniel Vetter wrote:
On Fri, Oct 16, 2020 at 07:46:41PM +0800, Shawn Guo wrote:
Indeed! Adding drm_crtc_vblank_reset() into driver crtc reset hook removes the WARNING for me. Really appreciate your comments, Daniel!
This should work automatically if you're using the atomic state helpers. Please try to unify as much as possible, so you're not missing any future bugfixes in this area. Although I thought I've completely reviewed all drivers to fix as many as possible for this bug. Are you on some older kernel that didn't have this? Maybe good idea to submit the bugfix in upstream to stable, if that's the case.
Yes, I'm running a 4.19 stable kernel with msm/mdp5 device. The bug was addressed (unintentionally?) by one patch that is part of the series adding Nexus 5 display support. And later on, you commit 51f644b40b4b ("drm/atomic-helper: reset vblank on crtc reset") switches the driver to use atomic state helper.
Shawn