[PATCH 05/11] drm/i915: Check lane count when determining FEC support

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

ICL doesn't support FEC with a x1 DP link. Make sure
we don't try to enable FEC in such cases.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index b27b4fb71ed7..9ac199444155 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1218,7 +1218,8 @@ static bool intel_dp_source_supports_fec(struct intel_dp *intel_dp,
 	if (DISPLAY_VER(dev_priv) >= 12)
 		return true;
 
-	if (DISPLAY_VER(dev_priv) == 11 && encoder->port != PORT_A)
+	if (DISPLAY_VER(dev_priv) == 11 &&
+	    encoder->port != PORT_A && pipe_config->lane_count != 1)
 		return true;
 
 	return false;
@@ -1234,7 +1235,7 @@ static bool intel_dp_supports_fec(struct intel_dp *intel_dp,
 static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
 				  const struct intel_crtc_state *crtc_state)
 {
-	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && !crtc_state->fec_enable)
+	if (!intel_dp_is_edp(intel_dp) && !crtc_state->fec_enable)
 		return false;
 
 	return intel_dsc_source_support(crtc_state) &&
@@ -1580,15 +1581,6 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 	int pipe_bpp;
 	int ret;
 
-	pipe_config->fec_enable = !intel_dp_is_edp(intel_dp) &&
-		intel_dp_supports_fec(intel_dp, pipe_config);
-
-	if (!intel_dp_supports_dsc(intel_dp, pipe_config))
-		return -EINVAL;
-
-	if (!intel_dp_dsc_supports_format(intel_dp, pipe_config->output_format))
-		return -EINVAL;
-
 	if (compute_pipe_bpp)
 		pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, conn_state->max_requested_bpc);
 	else
@@ -1615,6 +1607,15 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 	pipe_config->port_clock = limits->max_rate;
 	pipe_config->lane_count = limits->max_lane_count;
 
+	pipe_config->fec_enable = !intel_dp_is_edp(intel_dp) &&
+		intel_dp_supports_fec(intel_dp, pipe_config);
+
+	if (!intel_dp_supports_dsc(intel_dp, pipe_config))
+		return -EINVAL;
+
+	if (!intel_dp_dsc_supports_format(intel_dp, pipe_config->output_format))
+		return -EINVAL;
+
 	if (intel_dp_is_edp(intel_dp)) {
 		pipe_config->dsc.compressed_bpp =
 			min_t(u16, drm_edp_dsc_sink_output_bpp(intel_dp->dsc_dpcd) >> 4,
-- 
2.39.2