ACK/Cmnt: [SRU][H/raspi][PATCH 0/7] HDMI does not display anything with Impish RPi desktop image (LP: #1944397)

Tim Gardner tim.gardner at
Tue Oct 5 11:33:46 UTC 2021

Acked-by: Tim Gardner <tim.gardner at>

I have to trust that you can _see_ that this patch set is working, but 
there really isn't any test results in the bug report after you declared 
that the next step was to revert the vc4 breakage.

On 10/4/21 12:16 PM, Juerg Haefliger wrote:
> [ Impact ]
> The desktop does not come up and the screen stays blank when using 'dtoverlay=vc4-kms-v3d' on a Pi 4 (as is the case in raspi desktop images). If the desktop does come up, playing video freezes the desktop and/or the system. The kernel log shows loads of WARNINGs and potentially firmware errors.
> [ Test Case ]
> Use a raspi desktop image, play video (youtube or VLC), move windows around, switch to and from fullscreen video playback.
> [ Where problems could occur ]
> The fixes are all local to the VC4 driver so (new) issues should only show up when that driver is in use. Potential problems are UI freezes, kernel stalls and crashes.
> [ Original Description ]
> See LP: #1944397.

Tim Gardner
Canonical, Inc

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