Commit a8baec46 authored Apr 17, 2024 by Ilya Bakoulin Committed by Alex Deucher Apr 30, 2024

drm/amd/display: Fix FEC_READY write on DP LT

[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>

parent 523ee6f4

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_phy.c

+6 −8

Original line number	Diff line number	Diff line
		@@ -151,7 +151,6 @@ 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;

		status = core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
		@@ -161,7 +160,6 @@ enum dc_status dp_set_fec_ready(struct dc_link *link, const struct link_resource
		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) {
		fec_config = 0;