drm/i915/psr: Add psr sink error status into sink status debugfs

Normally PSR errors detected by the panel are triggering HPD interrupt and
seen as error in dmesg. Some panels are not triggering the interrupt even
it is requested and they are detecting error. Due to this it would be good
to have possibility to check panel detected errors. Add PSR error status
into PSR sink status debugfs interface.
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230828083107.1520501-1-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_psr.c

@@ -23,6 +23,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_damage_helper.h>
+#include <drm/drm_debugfs.h>
 
 #include "i915_drv.h"
 #include "i915_reg.h"
@@ -3159,7 +3160,7 @@ static int i915_psr_sink_status_show(struct seq_file *m, void *data)
 	};
 	const char *str;
 	int ret;
-	u8 val;
+	u8 status, error_status;
 
 	if (!CAN_PSR(intel_dp)) {
 		seq_puts(m, "PSR Unsupported\n");
@@ -3169,19 +3170,34 @@ static int i915_psr_sink_status_show(struct seq_file *m, void *data)
 	if (connector->base.status != connector_status_connected)
 		return -ENODEV;
 
-	ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS, &val);
-	if (ret != 1)
-		return ret < 0 ? ret : -EIO;
+	ret = psr_get_status_and_error_status(intel_dp, &status, &error_status);
+	if (ret)
+		return ret;
 
-	val &= DP_PSR_SINK_STATE_MASK;
-	if (val < ARRAY_SIZE(sink_status))
-		str = sink_status[val];
+	status &= DP_PSR_SINK_STATE_MASK;
+	if (status < ARRAY_SIZE(sink_status))
+		str = sink_status[status];
 	else
 		str = "unknown";
 
-	seq_printf(m, "Sink PSR status: 0x%x [%s]\n", val, str);
+	seq_printf(m, "Sink PSR status: 0x%x [%s]\n", status, str);
 
-	return 0;
+	seq_printf(m, "Sink PSR error status: 0x%x", error_status);
+
+	if (error_status & (DP_PSR_RFB_STORAGE_ERROR |
+			    DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR |
+			    DP_PSR_LINK_CRC_ERROR))
+		seq_puts(m, ":\n");
+	else
+		seq_puts(m, "\n");
+	if (error_status & DP_PSR_RFB_STORAGE_ERROR)
+		seq_puts(m, "\tPSR RFB storage error\n");
+	if (error_status & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
+		seq_puts(m, "\tPSR VSC SDP uncorrectable error\n");
+	if (error_status & DP_PSR_LINK_CRC_ERROR)
+		seq_puts(m, "\tPSR Link CRC error\n");
+
+	return ret;
 }
 DEFINE_SHOW_ATTRIBUTE(i915_psr_sink_status);