[PATCH v2] drm/mediatek: Add wait_event_timeout when disabling plane

[Chun-Kuang Hu]

Hi, Jason:

Jason-JH Lin (林睿祥) <Jason-JH.Lin at mediatek.com> 於 2025年6月25日 週三 下午3:40寫道：
>
> On Wed, 2025-06-25 at 06:54 +0000, CK Hu (胡俊光) wrote:
> > On Tue, 2025-06-24 at 19:31 +0800, Jason-JH Lin wrote:
> > > Our hardware registers are set through GCE, not by the CPU.
> > > DRM might assume the hardware is disabled immediately after calling
> > > atomic_disable() of drm_plane, but it is only truly disabled after
> > > the
> > > GCE IRQ is triggered.
> > >
> > > Additionally, the cursor plane in DRM uses async_commit, so DRM
> > > will
> > > not wait for vblank and will free the buffer immediately after
> > > calling
> > > atomic_disable().
> > >
> > > To prevent the framebuffer from being freed before the layer
> > > disable
> > > settings are configured into the hardware, which can cause an IOMMU
> > > fault error, a wait_event_timeout has been added to wait for the
> > > ddp_cmdq_cb() callback,indicating that the GCE IRQ has been
> > > triggered.
> > >
> > > Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC
> > > MT8173.")
> >
> > This patch looks good to me, so
> >
> > Reviewed-by: CK Hu <ck.hu at mediatek.com>
> >
> > But fixes patch is not correct.
> > In "drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.", it does
> > not support cmdq.
> > The first patch to support cmdq is 2f965be7f900 "drm/mediatek: apply
> > CMDQ control flow"
> > I would change fixes tag when I apply this patch.
> >
>
> Thank you very much!
>
> Regards,
> Jason-JH Lin

Applied to mediatek-drm-fixes [1], thanks.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes

Regards,
Chun-Kuang.

>
> > > Signed-off-by: Jason-JH Lin <jason-jh.lin at mediatek.com>
> > > Reviewed-by: AngeloGioacchino Del Regno
> > > <angelogioacchino.delregno at collabora.com>
>