[PATCH 0/6] drm/vc4: kms: Misc fixes for HVS commits

[Jian-Hong Pan]

Maxime Ripard <maxime at cerno.tech> 於 2021年11月15日 週一 下午7:31寫道：
>
> Hi,
>
> The conversion to DRM commit helpers (f3c420fe19f8, "drm/vc4: kms: Convert to
> atomic helpers") introduced a number of issues in corner cases, most of them
> showing themselves in the form of either a vblank timeout or use-after-free
> error.
>
> These patches should fix most of them, some of them still being debugged.
>
> Maxime
>
> Maxime Ripard (6):
>   drm/vc4: kms: Wait for the commit before increasing our clock rate
>   drm/vc4: kms: Fix return code check
>   drm/vc4: kms: Add missing drm_crtc_commit_put
>   drm/vc4: kms: Clear the HVS FIFO commit pointer once done
>   drm/vc4: kms: Don't duplicate pending commit
>   drm/vc4: kms: Fix previous HVS commit wait
>
>  drivers/gpu/drm/vc4/vc4_kms.c | 36 ++++++++++++++---------------------
>  1 file changed, 14 insertions(+), 22 deletions(-)
>
> --
> 2.33.1
>

Thanks to Maxime's information!

I tried to applied this patch series based on the latest mainline
kernel at commit commit 8ab774587903 ("Merge tag 'trace-v5.16-5' of
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace"),
which almost equals "tags/v5.16-rc1" and tested it on RPi 4B.
However, the system hangs and becomes dead at the kernel message:

[drm] Initialized vc4 0.0.0 20140616 for gpu on minor 0

The full dmesg can be found at
https://bugzilla.kernel.org/attachment.cgi?id=299603

If I revert the patch series to the original mainline kernel, system
can boot up.

BR,
Jian-Hong Pan