[PATCH v2 09/12] drm/msm/dp: remove redundant checks related to ST_DISPLAY_OFF in plug handler

[Dmitry Baryshkov]

On Fri, Aug 08, 2025 at 05:35:21PM -0700, Jessica Zhang wrote:
> From: Abhinav Kumar <quic_abhinavk at quicinc.com>
> 
> In commit 8ede2ecc3e5ee ("drm/msm/dp: Add DP compliance tests on Snapdragon
> Chipsets"), checks were introduced to avoid handling any plug event in
> ST_DISPLAY_OFF state.
> 
> Even if we do get hpd events, after the bridge was disabled,
> it should get handled. Moreover, its unclear under what circumstances
> these events will fire because ST_DISPLAY_OFF means that the link was
> still connected but only the bridge was disabled. If the link was
> untouched, then interrupts shouldn't fire.
> 
> Even in the case of the DP compliance equipment, it should be raising these
> interrupts during the start of the test which is usually accompanied with
> either a HPD pulse or a IRQ HPD but after the bridge is disabled it should
> be fine to handle these anyway. In the absence of a better reason to keep
> these checks, drop these and if any other issues do arise, it should be
> handled in a different way.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> Signed-off-by: Jessica Zhang <jessica.zhang at oss.qualcomm.com>
> ---
> Note: Taken from https://patchwork.freedesktop.org/series/142010/
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 3 ---
>  1 file changed, 3 deletions(-)

I think this patch and the next one should be folded into the 'drop the
HPD state machine' patch. It would be easier to review.

> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index eabd6e6981fb..dd3fdeaacc91 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -495,9 +495,6 @@ static int msm_dp_hpd_plug_handle(struct msm_dp_display_private *dp, u32 data)
>  	drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
>  			dp->msm_dp_display.connector_type, state);
>  
> -	if (state == ST_DISPLAY_OFF)
> -		return 0;
> -
>  	if (state == ST_MAINLINK_READY || state == ST_CONNECTED)
>  		return 0;
>  
> 
> -- 
> 2.50.1
> 

-- 
With best wishes
Dmitry