Quoting Kuogee Hsieh (2021-08-02 13:20:55)

Currently at dp_pm_resume() is_connected state is decided base on hpd connection status only. This will put is_connected in wrongly "true" state at the scenario that dongle attached to DUT but without hmdi cable connecting to it. Fix this problem by adding read sink count from dongle and decided is_connected state base on both sink count and hpd connection status.

Changes in v2: -- remove dp_get_sink_count() cand call drm_dp_read_sink_count()

Fixes: d9aa6571b28ba ("drm/msm/dp: check sink_count before update is_connected status") Signed-off-by: Kuogee Hsieh khsieh@codeaurora.org

---

drivers/gpu/drm/msm/dp/dp_display.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 8b69114..6dcb78e 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1403,6 +1403,7 @@ static int dp_pm_resume(struct device *dev) struct msm_dp *dp_display = platform_get_drvdata(pdev); struct dp_display_private *dp; u32 status;

'status' is unused now, right? The compiler should be complaining about unused local variables.

•   int sink_count = 0;
  
    dp = container_of(dp_display, struct dp_display_private, dp_display);
  

xlog(__func__, 1,0,0, dp->core_initialized, dp_display->power_on); @@ -1417,15 +1418,26 @@ xlog(__func__, 1,0,0, dp->core_initialized, dp_display->power_on);

    dp_catalog_ctrl_hpd_config(dp->catalog);

•   status = dp_catalog_link_is_connected(dp->catalog);
  

•   /*
  

•    * set sink to normal operation mode -- D0
  

•    * before dpcd read
  

•    */
  

•   dp_link_psm_config(dp->link, &dp->panel->link_info, false);
  

•   /* if sink conencted, do dpcd read sink count */
  

•   if ((status = dp_catalog_link_is_connected(dp->catalog))) {
  

•           sink_count = drm_dp_read_sink_count(dp->aux);
  

•           if (sink_count < 0)
  

•                   sink_count = 0;
  

•   }
  
  

•   dp->link->sink_count = sink_count;
    /*
     * can not declared display is connected unless
     * HDMI cable is plugged in and sink_count of
     * dongle become 1
     */
  

-xlog(__func__, 0x12,0,0, 0, dp->link->sink_count);

•   if (status && dp->link->sink_count)
  

•   if (dp->link->sink_count)
            dp->dp_display.is_connected = true;
    else
            dp->dp_display.is_connected = false;