drm/amd/display: Disable error correction if it's not supported

From Cruise
27bbf0b1cac9866666878421d57c15a78867f7cd in linux-6.6.y/6.6.52
a8ac994cf0693a1ce59410995594e56124a1c79f in mainline linux

diff --git a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_phy.c b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_phy.c
index 4db8762..b16e09c 100644 (file)
--- a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_phy.c
+++ b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_phy.c
@@ -143,32 +143,27 @@ enum dc_status dp_set_fec_ready(struct dc_link *link, const struct link_resource
 
        link_enc = link_enc_cfg_get_link_enc(link);
        ASSERT(link_enc);
+       if (link_enc->funcs->fec_set_ready == NULL)
+               return DC_NOT_SUPPORTED;
 
-       if (!dp_should_enable_fec(link))
-               return status;
-
-       if (link_enc->funcs->fec_set_ready &&
-                       link->dpcd_caps.fec_cap.bits.FEC_CAPABLE) {
-               if (ready) {
+       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,
-                                       &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;
-                       } else {
-                               link_enc->funcs->fec_set_ready(link_enc, false);
-                               link->fec_state = dc_link_fec_not_ready;
-                               dm_error("dpcd write failed to set fec_ready");
                        }
-               } else if (link->fec_state == dc_link_fec_ready) {
+               }
+       } else {
+               if (link->fec_state == dc_link_fec_ready) {
                        fec_config = 0;
-                       status = core_link_write_dpcd(link,
-                                       DP_FEC_CONFIGURATION,
-                                       &fec_config,
-                                       sizeof(fec_config));
+                       core_link_write_dpcd(link, DP_FEC_CONFIGURATION,
+                               &fec_config, sizeof(fec_config));
+
                        link_enc->funcs->fec_set_ready(link_enc, false);
                        link->fec_state = dc_link_fec_not_ready;
                }
@@ -183,14 +178,12 @@ void dp_set_fec_enable(struct dc_link *link, bool enable)
 
        link_enc = link_enc_cfg_get_link_enc(link);
        ASSERT(link_enc);
-
-       if (!dp_should_enable_fec(link))
+       if (link_enc->funcs->fec_set_enable == NULL)
                return;
 
-       if (link_enc->funcs->fec_set_enable &&
-                       link->dpcd_caps.fec_cap.bits.FEC_CAPABLE) {
-               if (link->fec_state == dc_link_fec_ready && enable) {
-                       /* Accord to DP spec, FEC enable sequence can first
+       if (enable && dp_should_enable_fec(link)) {
+               if (link->fec_state == dc_link_fec_ready) {
+                       /* According to DP spec, FEC enable sequence can first
                         * be transmitted anytime after 1000 LL codes have
                         * been transmitted on the link after link training
                         * completion. Using 1 lane RBR should have the maximum
@@ -200,7 +193,9 @@ void dp_set_fec_enable(struct dc_link *link, bool enable)
                        udelay(7);
                        link_enc->funcs->fec_set_enable(link_enc, true);
                        link->fec_state = dc_link_fec_enabled;
-               } else if (link->fec_state == dc_link_fec_enabled && !enable) {
+               }
+       } else {
+               if (link->fec_state == dc_link_fec_enabled) {
                        link_enc->funcs->fec_set_enable(link_enc, false);
                        link->fec_state = dc_link_fec_ready;
                }