diff options
| author | Yongqiang Sun <yongqiang.sun@amd.com> | 2018-03-07 17:12:53 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2018-04-11 21:07:36 +0300 |
| commit | 3c1a312aa4e4201efa8719e70a6dccd3acd6eba4 (patch) | |
| tree | 9fe6d13b6b8fa9112b4b0235cd6998eef90bf785 | |
| parent | ba0a5aaa867d77cedb2cd6ad9e647243d9ba9650 (diff) | |
| download | linux-3c1a312aa4e4201efa8719e70a6dccd3acd6eba4.tar.xz | |
drm/amd/display: Retry when read dpcd caps failed.
Some DP panel not detected intermittently due to read dpcd
caps failed when doing hot plug.
[root cause] DC_HPD_CONNECT_INT_DELAY is set to 0, not delay
after HPD toggle and read dpcd data, while some panel need 4ms defer
to read.
[solution] Add a retry when read failed.
Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 3b5053570229..b86325bb636f 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -2278,6 +2278,8 @@ static bool retrieve_link_cap(struct dc_link *link) union edp_configuration_cap edp_config_cap; union dp_downstream_port_present ds_port = { 0 }; enum dc_status status = DC_ERROR_UNEXPECTED; + uint32_t read_dpcd_retry_cnt = 3; + int i; memset(dpcd_data, '\0', sizeof(dpcd_data)); memset(&down_strm_port_count, @@ -2285,11 +2287,15 @@ static bool retrieve_link_cap(struct dc_link *link) memset(&edp_config_cap, '\0', sizeof(union edp_configuration_cap)); - status = core_link_read_dpcd( - link, - DP_DPCD_REV, - dpcd_data, - sizeof(dpcd_data)); + for (i = 0; i < read_dpcd_retry_cnt; i++) { + status = core_link_read_dpcd( + link, + DP_DPCD_REV, + dpcd_data, + sizeof(dpcd_data)); + if (status == DC_OK) + break; + } if (status != DC_OK) { dm_error("%s: Read dpcd data failed.\n", __func__); |