[Intel-gfx] [PATCH 01/19] drm/i915/dp: Sanitize DPCD revision check in intel_dp_get_dsc_sink_cap()

[Imre Deak <imre.deak@intel.com>]

Check only the eDP or the DP specific DPCD revision depending on the
sink type. Pass the corresponding revision to the function, which allows
getting the DSC caps of a branch device (in an MST topology, which has
its own DPCD and so DPCD revision).

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 0ef7cb8134b66..1bd11f9e308c1 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3467,7 +3467,7 @@ bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
 	return dprx & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED;
 }
 
-static void intel_dp_get_dsc_sink_cap(struct intel_dp *intel_dp)
+static void intel_dp_get_dsc_sink_cap(u8 dpcd_rev, struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 
@@ -3481,8 +3481,8 @@ static void intel_dp_get_dsc_sink_cap(struct intel_dp *intel_dp)
 	intel_dp->fec_capable = 0;
 
 	/* Cache the DSC DPCD if eDP or DP rev >= 1.4 */
-	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x14 ||
-	    intel_dp->edp_dpcd[0] >= DP_EDP_14) {
+	if ((intel_dp_is_edp(intel_dp) && dpcd_rev >= DP_EDP_14) ||
+	    (!intel_dp_is_edp(intel_dp) && dpcd_rev >= 0x14)) {
 		if (drm_dp_dpcd_read(&intel_dp->aux, DP_DSC_SUPPORT,
 				     intel_dp->dsc_dpcd,
 				     sizeof(intel_dp->dsc_dpcd)) < 0)
@@ -3674,7 +3674,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
 
 	/* Read the eDP DSC DPCD registers */
 	if (HAS_DSC(dev_priv))
-		intel_dp_get_dsc_sink_cap(intel_dp);
+		intel_dp_get_dsc_sink_cap(intel_dp->edp_dpcd[0],
+					  intel_dp);
 
 	/*
 	 * If needed, program our source OUI so we can make various Intel-specific AUX services
@@ -5384,7 +5385,8 @@ intel_dp_detect(struct drm_connector *connector,
 
 	/* Read DP Sink DSC Cap DPCD regs for DP v1.4 */
 	if (HAS_DSC(dev_priv))
-		intel_dp_get_dsc_sink_cap(intel_dp);
+		intel_dp_get_dsc_sink_cap(intel_dp->dpcd[DP_DPCD_REV],
+					  intel_dp);
 
 	intel_dp_configure_mst(intel_dp);
 
-- 
2.39.2