Re: [PATCH v2 2/7] drm/msm/dp: reduce link rate if failed at link training 1

Quoting Kuogee Hsieh (2021-07-13 08:54:02)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 27fb0f0..92cf331 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1634,6 +1617,24 @@ void dp_ctrl_handle_sink_request(struct dp_ctrl *dp_ctrl) } }

+static bool dp_ctrl_clock_recovery_any_ok(

•                   const u8 link_status[DP_LINK_STATUS_SIZE],
  

•                   int lane_count)
  

+{

•   int lane_cnt;
  

•   /*
  

•    * only interested in the lane number after reduced
  

•    * lane_cnt = 4, then only interested in 2 lanes
  

•    * lane_cnt = 2, then only interested in 1 lane
  

•    */
  

•   lane_cnt = lane_count >> 1;
  

•   if (lane_cnt == 0)
  

•           return false;
  

•   return drm_dp_clock_recovery_ok(link_status, lane_count);
  

This doesn't work? Because drm_dp_clock_recovery_ok() requires every lane to be OK whereas this function wants any lane to be OK? It may make sense to have drm_dp_clock_recovery_ok() return false if lane_count == 0 too.

+}

int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) { int rc = 0;