From: Derek Lai <[email protected]> [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 <[email protected]> Reviewed-by: Tony Cheng <[email protected]> Acked-by: Leo Li <[email protected]> --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 7 +++++++ 1 file changed, 7 insertions(+) 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 1e051e953610..4b82b86f1e6a 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -530,6 +530,7 @@ 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++) { @@ -574,6 +575,12 @@ 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( -- 2.22.0 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
