drm/msm/dp: check sink_count before update is_connected status

Link status is different from display connected status in the case
of something like an Apple dongle where the type-c plug can be
connected, and therefore the link is connected, but no sink is
connected until an HDMI cable is plugged into the dongle.
The sink_count of DPCD of dongle will increase to 1 once an HDMI
cable is plugged into the dongle so that display connected status
will become true. This checking also apply at pm_resume.

Changes in v4:
-- none

Fixes: 94e58e2d06e3 ("drm/msm/dp: reset dp controller only at boot up and pm_resume")
Reported-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Fixes: 8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
Link: https://lore.kernel.org/r/1619048258-8717-2-git-send-email-khsieh@codeaurora.org
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 5a39da6e1eaf2779a2944a81490e22f8bc0374d2..0ba71c7a8dd4d05456e176c0301f0e9ed4649b89 100644 (file)
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -586,10 +586,8 @@ static int dp_connect_pending_timeout(struct dp_display_private *dp, u32 data)
        mutex_lock(&dp->event_mutex);
 
        state = dp->hpd_state;
-       if (state == ST_CONNECT_PENDING) {
-               dp_display_enable(dp, 0);
+       if (state == ST_CONNECT_PENDING)
                dp->hpd_state = ST_CONNECTED;
-       }
 
        mutex_unlock(&dp->event_mutex);
 
@@ -669,10 +667,8 @@ static int dp_disconnect_pending_timeout(struct dp_display_private *dp, u32 data
        mutex_lock(&dp->event_mutex);
 
        state =  dp->hpd_state;
-       if (state == ST_DISCONNECT_PENDING) {
-               dp_display_disable(dp, 0);
+       if (state == ST_DISCONNECT_PENDING)
                dp->hpd_state = ST_DISCONNECTED;
-       }
 
        mutex_unlock(&dp->event_mutex);
 
@@ -1272,7 +1268,12 @@ static int dp_pm_resume(struct device *dev)
 
        status = dp_catalog_link_is_connected(dp->catalog);
 
-       if (status)
+       /*
+        * can not declared display is connected unless
+        * HDMI cable is plugged in and sink_count of
+        * dongle become 1
+        */
+       if (status && dp->link->sink_count)
                dp->dp_display.is_connected = true;
        else
                dp->dp_display.is_connected = false;