6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Bakoulin <ilya.bakoulin@xxxxxxx>
[ Upstream commit a8baec4623aedf36d50767627f6eae5ebf07c6fb ]
[Why/How]
We can miss writing FEC_READY in some cases before LT start, which
violates DP spec. Remove the condition guarding the DPCD write so that
the write happens unconditionally.
Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Wenjing Liu <wenjing.liu@xxxxxxx>
Acked-by: Wayne Lin <wayne.lin@xxxxxxx>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../amd/display/dc/link/protocols/link_dp_phy.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_phy.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_phy.c
index f06f708ba5c8..9bde0c8bf914 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_phy.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_phy.c
@@ -147,16 +147,14 @@ enum dc_status dp_set_fec_ready(struct dc_link *link, const struct link_resource
return DC_NOT_SUPPORTED;
if (ready && dp_should_enable_fec(link)) {
- if (link->fec_state == dc_link_fec_not_ready) {
- fec_config = 1;
+ fec_config = 1;
- status = core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
- &fec_config, sizeof(fec_config));
+ status = core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
+ &fec_config, sizeof(fec_config));
- if (status == DC_OK) {
- link_enc->funcs->fec_set_ready(link_enc, true);
- link->fec_state = dc_link_fec_ready;
- }
+ if (status == DC_OK) {
+ link_enc->funcs->fec_set_ready(link_enc, true);
+ link->fec_state = dc_link_fec_ready;
}
} else {
if (link->fec_state == dc_link_fec_ready) {
--
2.43.0
