[PATCH v2 07/20] drm/msm/dp: Serialize stream operations with HPD processing

[Dmitry Baryshkov]

On Fri, Oct 09, 2026 at 11:15:59AM +0800, Xilin Wu wrote:
> HPD PHY test requests stop and restart the mainlink under plugged_lock,

What is HPD PHY test?

> but atomic stream enable and disable do not take that lock. Both paths
> can check a resource flag before either updates it and acquire duplicate

Which flag?

> clock or PHY references. They can also reset a link while the other path
> is training it or enabling video.
> 
> Hold plugged_lock across link preparation, stream enable and post-enable,
> and protect stream disable and PSR transitions with the same lock. Add
> lock assertions to the internal stream helpers. Acquire the runtime PM
> reference and handle the eDP plug event before entering the critical
> section, and leave audio shutdown waits and runtime PM release outside.
> 
> This provides the serialization required by PHY ownership tracking and
> the subsequent stream enable rollback paths.
> 
> Assisted-by: LLM
> Signed-off-by: Xilin Wu <sophon at radxa.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 42 ++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)
> 

-- 
With best wishes
Dmitry