[Intel-gfx] [PATCH v6 5/5] drm/i915/psr: Enable CRC check in the static frame on the sink side

[José Roberto de Souza]

Sink can be configured to calculate the CRC over the static frame and
compare with the CRC calculated and transmited in the VSC SDP by
source, if there is a mismatch sink will do a short pulse in HPD
and set DP_PSR_LINK_CRC_ERROR in DP_PSR_ERROR_STATUS.

Spec: 7723

v6:
andling DP_PSR_LINK_CRC_ERROR here and remove "bdw+" from commit
message

v4:
patch moved to after 'drm/i915/psr: Avoid PSR exit max time timeout'
to avoid touch in 2 patches EDP_PSR_DEBUG.

v3:
disabling PSR instead of exiting on error

Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |  1 +
 drivers/gpu/drm/i915/intel_psr.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index caad19f5f557..43db91c19f52 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4044,6 +4044,7 @@ enum {
 #define   EDP_PSR_SKIP_AUX_EXIT			(1 << 12)
 #define   EDP_PSR_TP1_TP2_SEL			(0 << 11)
 #define   EDP_PSR_TP1_TP3_SEL			(1 << 11)
+#define   EDP_PSR_CRC_ENABLE			(1 << 10) /* BDW+ */
 #define   EDP_PSR_TP2_TP3_TIME_500us		(0 << 8)
 #define   EDP_PSR_TP2_TP3_TIME_100us		(1 << 8)
 #define   EDP_PSR_TP2_TP3_TIME_2500us		(2 << 8)
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 11d728770196..bdb644268edb 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -360,6 +360,8 @@ static void hsw_psr_enable_sink(struct intel_dp *intel_dp)
 
 	if (dev_priv->psr.link_standby)
 		dpcd_val |= DP_PSR_MAIN_LINK_ACTIVE;
+	if (!dev_priv->psr.psr2_enabled && INTEL_GEN(dev_priv) >= 8)
+		dpcd_val |= DP_PSR_CRC_VERIFICATION;
 	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, dpcd_val);
 
 	drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
@@ -415,6 +417,9 @@ static void hsw_activate_psr1(struct intel_dp *intel_dp)
 	else
 		val |= EDP_PSR_TP1_TP2_SEL;
 
+	if (INTEL_GEN(dev_priv) >= 8)
+		val |= EDP_PSR_CRC_ENABLE;
+
 	val |= I915_READ(EDP_PSR_CTL) & EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK;
 	I915_WRITE(EDP_PSR_CTL, val);
 }
@@ -1012,7 +1017,8 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp)
 	struct i915_psr *psr = &dev_priv->psr;
 	u8 val;
 	const u8 errors = DP_PSR_RFB_STORAGE_ERROR |
-			  DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR;
+			  DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR |
+			  DP_PSR_LINK_CRC_ERROR;
 
 	if (!CAN_PSR(dev_priv) || !intel_dp_is_edp(intel_dp))
 		return;
@@ -1041,6 +1047,8 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp)
 		DRM_DEBUG_KMS("PSR RFB storage error, disabling PSR\n");
 	if (val & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
 		DRM_DEBUG_KMS("PSR VSC SDP uncorrectable error, disabling PSR\n");
+	if (val & DP_PSR_LINK_CRC_ERROR)
+		DRM_ERROR("PSR Link CRC error, disabling PSR\n");
 
 	if (val & ~errors)
 		DRM_ERROR("PSR_ERROR_STATUS unhandled errors %x\n",
-- 
2.17.1