[PATCH] Revert "drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes"

[Abhinav Kumar]

On 2/27/2024 2:08 PM, Dmitry Baryshkov wrote:
> This reverts commit e467e0bde881 ("drm/msm/dp: use
> drm_bridge_hpd_notify() to report HPD status changes").
> 
> The commit changed the way how the MSM DP driver communicates
> HPD-related events to the userspace. The mentioned commit made some of
> the HPD events being reported earlier. This way userspace starts poking
> around. It interacts in a bad way with the dp_bridge_detect and the
> driver's state machine, ending up either with the very long delays
> during hotplug detection or even inability of the DP driver to report
> the display as connected.
> 
> A proper fix will involve redesigning of the HPD handling in the MSM DP
> driver. It is underway, but it will be intrusive and can not be thought
> about as a simple fix for the issue. Thus, revert the offending commit.
> 

Yes, for fixing this on 6.9 I am fine with this.

I hope there were not other changes which were built on top of this. So 
it will be better if we retest internal HPD case as well with this.

We will do that in a day or two and give Tested-by.

> Fixes: e467e0bde881 ("drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes")
> Link: https://gitlab.freedesktop.org/drm/msm/-/issues/50
> Reported-by: Johan Hovold <johan at kernel.org>
> Link: https://lore.kernel.org/r/Zd3YPGmrprxv-N-O@hovoldconsulting.com/
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>   drivers/gpu/drm/msm/dp/dp_display.c | 20 ++++++++++++++++++--
>   1 file changed, 18 insertions(+), 2 deletions(-)
> 

For the change itself,


Reviewed-by: Abhinav Kumar <quic_abhinavk at quicinc.com>