6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ilya Bakoulin ilya.bakoulin@amd.com
[ 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@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Reviewed-by: Wenjing Liu wenjing.liu@amd.com Acked-by: Wayne Lin wayne.lin@amd.com Signed-off-by: Ilya Bakoulin ilya.bakoulin@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 --- .../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) {