diff options
| author | Derek Lai <Derek.Lai@amd.com> | 2019-06-18 14:55:57 +0800 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-07-18 14:18:10 -0500 |
| commit | 701c75cea29b725a5447c7a7d3b8b4c8472ab79a (patch) | |
| tree | 65e0a705463ef48ca2f7e75054e17107971664b0 /drivers/gpu/drm/amd/display/dc/core/dc_link.c | |
| parent | eced4bceed22114697a17295a768cebea1dbc2b0 (diff) | |
drm/amd/display: Read max down spread
[Why]
When launch D10.2, driver will write DPCD 0x107 with 0x00
[How]
Read MAX_DOWNSPREAD (0x0003h) then keep in current
link settings
Signed-off-by: Derek Lai <Derek.Lai@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/core/dc_link.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index 07533cc377fd..d685cde284ec 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -532,6 +532,7 @@ static void read_edp_current_link_settings_on_detect(struct dc_link *link) uint32_t read_dpcd_retry_cnt = 10; enum dc_status status = DC_ERROR_UNEXPECTED; int i; + union max_down_spread max_down_spread = { {0} }; // Read DPCD 00101h to find out the number of lanes currently set for (i = 0; i < read_dpcd_retry_cnt; i++) { @@ -576,6 +577,12 @@ static void read_edp_current_link_settings_on_detect(struct dc_link *link) link->cur_link_settings.link_rate = link_bw_set; link->cur_link_settings.use_link_rate_set = false; } + // Read DPCD 00003h to find the max down spread. + core_link_read_dpcd(link, DP_MAX_DOWNSPREAD, + &max_down_spread.raw, sizeof(max_down_spread)); + link->cur_link_settings.link_spread = + max_down_spread.bits.MAX_DOWN_SPREAD ? + LINK_SPREAD_05_DOWNSPREAD_30KHZ : LINK_SPREAD_DISABLED; } static bool detect_dp( |