[Intel-gfx] [PATCH v4 5/5] drm/i915/psr/bdw+: 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

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

Cc: 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 | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 140f6a27d696..ed34ccd81c7c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4038,6 +4038,7 @@ 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 177cd57b1029..cf72b79caf3f 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);
 }
@@ -1032,16 +1037,19 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp)
 		goto exit;
 	}
 
-	if (val & DP_PSR_RFB_STORAGE_ERROR) {
-		DRM_DEBUG_KMS("PSR RFB storage error, exiting PSR\n");
+	if (val & (DP_PSR_RFB_STORAGE_ERROR | DP_PSR_LINK_CRC_ERROR)) {
+		if (val & DP_PSR_RFB_STORAGE_ERROR)
+			DRM_DEBUG_KMS("PSR RFB storage error, disabling PSR\n");
+		if (val & DP_PSR_LINK_CRC_ERROR)
+			DRM_DEBUG_KMS("PSR Link CRC error, disabling PSR\n");
 		psr_disable(intel_dp);
 	}
-	if (val & (DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR | DP_PSR_LINK_CRC_ERROR))
+	if (val & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
 		DRM_ERROR("PSR_ERROR_STATUS not handled %x\n", val);
 	/* clear status register */
 	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS, val);
 
-	/* TODO: handle other PSR/PSR2 errors */
+	/* TODO: handle PSR2 errors */
 exit:
 	mutex_unlock(&psr->lock);
 }
-- 
2.17.1