On 8/10/2022 10:22 AM, Kuogee Hsieh wrote:
> dp_bridge_disable() is the first step toward tearing down main link.
> Its major function is to start transmitting idle pattern to replace
> video stream. This patch will check hpd_state to make sure main link
> is enabled before commit changes of main link's configuration to
> push idle pattern out to avoid system crashing due to main link clock
> is disabled while access main link registers.
Do you also want to give the full stack of unclocked access here?
>
> Changes in v2:
> -- changes Fixes patch
> -- fix eported-by
> -- add Closes tag
>
> Fixes: 375a126090b9 ("drm/msm/dp: tear down main link at unplug handle immediately")
> Reported-by: [email protected]
This is still incorrect. Should be:
Reported-by: Leonard Lausen <[email protected]>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/17
> Signed-off-by: Kuogee Hsieh <[email protected]>
> ---
> drivers/gpu/drm/msm/dp/dp_display.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index b36f8b6..678289a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1729,10 +1729,20 @@ void dp_bridge_disable(struct drm_bridge *drm_bridge)
> struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
> struct msm_dp *dp = dp_bridge->dp_display;
> struct dp_display_private *dp_display;
> + u32 state;
>
> dp_display = container_of(dp, struct dp_display_private, dp_display);
>
> + mutex_lock(&dp_display->event_mutex);
> +
> + state = dp_display->hpd_state;
> + if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) {
> + mutex_unlock(&dp_display->event_mutex);
> + return;
> + }
> +
> dp_ctrl_push_idle(dp_display->ctrl);
> + mutex_unlock(&dp_display->event_mutex);
> }
>
> void dp_bridge_post_disable(struct drm_bridge *drm_bridge)