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| author |   Derek Lai <Derek.Lai@amd.com> | 2019-06-18 14:55:57 +0800 |
|---|---|---|
| committer |   Alex Deucher <alexander.deucher@amd.com> | 2019-07-18 14:17:19 -0500 |
| commit | 12d0e503dd9e0576487b2f20577717b2a36fe0c5 (patch) | |
| tree | 07995f61c2b1b561ab5cee7809280bd109bd70e8 /drivers/gpu/drm/amd/display | |
| parent | drm/amd/display: Check for valid stream_encode (diff) | |
| download | linux-dev-12d0e503dd9e0576487b2f20577717b2a36fe0c5.tar.xz linux-dev-12d0e503dd9e0576487b2f20577717b2a36fe0c5.zip | |
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')
| -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 435d50356bad..652960c5548a 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( |