From: Austin Zheng austin.zheng@amd.com
[ Upstream commit 4a30cc2bd281fa176a68b5305cd3695d636152ad ]
[Why] Flash of corruption observed when UCLK switching after transitioning from DTBCLK to DPREFCLK on subVP(DP) + subVP(HDMI) config Scenario where DPREFCLK is required instead of DTBCLK is not expected
[How] Always set the DTBCLK source as DTBCLK0
Reviewed-by: Alvin Lee alvin.lee2@amd.com Acked-by: Tom Chung chiahsuan.chung@amd.com Signed-off-by: Austin Zheng austin.zheng@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c index 61ceff6bc0b19..921f58c0c729b 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c @@ -281,7 +281,8 @@ static void dccg32_set_dpstreamclk( struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
/* set the dtbclk_p source */ - dccg32_set_dtbclk_p_src(dccg, src, otg_inst); + /* always program refclk as DTBCLK. No use-case expected to require DPREFCLK as refclk */ + dccg32_set_dtbclk_p_src(dccg, DTBCLK0, otg_inst);
/* enabled to select one of the DTBCLKs for pipe */ switch (dp_hpo_inst) {