[PATCH v2] drm/xe/display: read PCON capability only when present

[Chaitanya Kumar Borah]

Avoid reading the PCON capabilities redundantly on non-branch devices.

v2:
 - Make commit description more accurate. (Imre)
 - Clear intel_dp->pcon_dsc_dpcd irrespective of presense of PCON. (Imre)

Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 277b40b13948..f48912f308df 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3726,6 +3726,9 @@ static void intel_dp_get_pcon_dsc_cap(struct intel_dp *intel_dp)
 
 	memset(intel_dp->pcon_dsc_dpcd, 0, sizeof(intel_dp->pcon_dsc_dpcd));
 
+	if (!drm_dp_is_branch(intel_dp->dpcd))
+		return;
+
 	if (drm_dp_dpcd_read(&intel_dp->aux, DP_PCON_DSC_ENCODER,
 			     intel_dp->pcon_dsc_dpcd,
 			     sizeof(intel_dp->pcon_dsc_dpcd)) < 0)
-- 
2.25.1