[PATCH 6.1.y 3/4] drm/i915/psr: Read Intel DPCD workaround register

["Jouni Högander" <jouni.hogander@intel.com>]

commit f30bece421a4ae34359254e1dc2a187a42b6af9b upstream.

Read Intel DPCD workaround register and store it into
intel_connector->dp.psr_caps. psr_caps was chosen as currently it contains
only PSR workaround for PSR2 SDP on prior scanline implementation.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260515095756.2799483-3-jouni.hogander@intel.com
(cherry picked from commit c48ff24d0f4ab7ad696b2d35ad64ce7e049c668c)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
---
 drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
 drivers/gpu/drm/i915/display/intel_psr.c           | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index a8bf91a21cb2..a26c082bdc32 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1637,6 +1637,7 @@ struct intel_dp {
 	u8 lttpr_phy_caps[DP_MAX_LTTPR_COUNT][DP_LTTPR_PHY_CAP_SIZE];
 	u8 fec_capable;
 	u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE];
+	u8 intel_wa_dpcd;
 	/* source rates */
 	int num_source_rates;
 	const int *source_rates;
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 505c3c4251a5..3e634873a097 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -31,6 +31,7 @@
 #include "intel_crtc.h"
 #include "intel_de.h"
 #include "intel_display_types.h"
+#include "intel_dpcd.h"
 #include "intel_dp_aux.h"
 #include "intel_hdmi.h"
 #include "intel_psr.h"
@@ -388,6 +389,12 @@ void intel_psr_init_dpcd(struct intel_dp *intel_dp)
 			intel_dp_get_su_granularity(intel_dp);
 		}
 	}
+
+	if (intel_dp->psr.sink_psr2_support)
+		drm_dp_dpcd_read(&intel_dp->aux,
+				 INTEL_DPCD_INTEL_WA_REGISTER_CAPS,
+				 &intel_dp->intel_wa_dpcd,
+				 sizeof(intel_dp->intel_wa_dpcd));
 }
 
 static void intel_psr_enable_sink(struct intel_dp *intel_dp)
-- 
2.43.0