[Intel-gfx] [PATCH] drm/edid: Dump valid EDIDs too

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Having the EDID available is often very beneficial for bug analysis,
even when the EDID itself is valid and not the direct cause of the
bug. So let's dump the EDID to dmesg even when it's valid. This
should also give us a better historical record of EDIDs for later
analysis.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_edid.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 134069f36482..1153b2f74c58 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1517,17 +1517,27 @@ drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
 	return ret == xfers ? 0 : -1;
 }
 
-static void connector_bad_edid(struct drm_connector *connector,
-			       u8 *edid, int num_blocks)
+static void connector_dump_edid(struct drm_connector *connector,
+				u8 *edid, int num_blocks,
+				bool valid)
 {
 	int i;
 
-	if (connector->bad_edid_counter++ && !(drm_debug & DRM_UT_KMS))
-		return;
+	if (valid) {
+		if (!(drm_debug & DRM_UT_KMS))
+			return;
+
+		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] EDID is valid:\n",
+			      connector->base.id, connector->name);
+	} else {
+		if (connector->bad_edid_counter++ && !(drm_debug & DRM_UT_KMS))
+			return;
+
+		dev_warn(connector->dev->dev,
+			 "[CONNECTOR:%d:%s] EDID is invalid:\n",
+			 connector->base.id, connector->name);
+	}
 
-	dev_warn(connector->dev->dev,
-		 "%s: EDID is invalid:\n",
-		 connector->name);
 	for (i = 0; i < num_blocks; i++) {
 		u8 *block = edid + i * EDID_LENGTH;
 		char prefix[20];
@@ -1539,7 +1549,7 @@ static void connector_bad_edid(struct drm_connector *connector,
 		else
 			sprintf(prefix, "\t[%02x] GOOD ", i);
 
-		print_hex_dump(KERN_WARNING,
+		print_hex_dump(valid ? KERN_DEBUG : KERN_WARNING,
 			       prefix, DUMP_PREFIX_NONE, 16, 1,
 			       block, EDID_LENGTH, false);
 	}
@@ -1580,8 +1590,10 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 	if (!override)
 		override = drm_load_edid_firmware(connector);
 
-	if (!IS_ERR_OR_NULL(override))
-		return override;
+	if (!IS_ERR_OR_NULL(override)) {
+		edid = (u8 *)override;
+		goto done;
+	}
 
 	if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
 		return NULL;
@@ -1628,7 +1640,7 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 	if (valid_extensions != edid[0x7e]) {
 		u8 *base;
 
-		connector_bad_edid(connector, edid, edid[0x7e] + 1);
+		connector_dump_edid(connector, edid, edid[0x7e] + 1, false);
 
 		edid[EDID_LENGTH-1] += edid[0x7e] - valid_extensions;
 		edid[0x7e] = valid_extensions;
@@ -1652,10 +1664,13 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 		edid = new;
 	}
 
+done:
+	connector_dump_edid(connector, edid, edid[0x7e] + 1, true);
+
 	return (struct edid *)edid;
 
 carp:
-	connector_bad_edid(connector, edid, 1);
+	connector_dump_edid(connector, edid, 1, false);
 out:
 	kfree(edid);
 	return NULL;
-- 
2.16.1