drm/edid: pass struct edid to connector_bad_edid()

Avoid casting here and there, and make it const.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4f9fdc961dfd9b36f4649e8ba57d05e43375fc92.1649685475.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -1967,7 +1967,7 @@ drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
 }
 
 static void connector_bad_edid(struct drm_connector *connector,
-			       u8 *edid, int num_blocks)
+			       const struct edid *edid, int num_blocks)
 {
 	int i;
 	u8 last_block;
@@ -1978,22 +1978,19 @@ static void connector_bad_edid(struct drm_connector *connector,
 	 * of 0x7e in the EDID of the _index_ of the last block in the
 	 * combined chunk of memory.
 	 */
-	last_block = edid[0x7e];
+	last_block = edid->extensions;
 
 	/* Calculate real checksum for the last edid extension block data */
 	if (last_block < num_blocks)
 		connector->real_edid_checksum =
-			edid_block_compute_checksum(edid + last_block * EDID_LENGTH);
+			edid_block_compute_checksum(edid + last_block);
 
 	if (connector->bad_edid_counter++ && !drm_debug_enabled(DRM_UT_KMS))
 		return;
 
 	drm_dbg_kms(connector->dev, "%s: EDID is invalid:\n", connector->name);
-	for (i = 0; i < num_blocks; i++) {
-		u8 *block = edid + i * EDID_LENGTH;
-
-		edid_block_dump(KERN_DEBUG, block, i);
-	}
+	for (i = 0; i < num_blocks; i++)
+		edid_block_dump(KERN_DEBUG, edid + i, i);
 }
 
 /* Get override or firmware EDID */
@@ -2139,7 +2136,7 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 	}
 
 	if (invalid_blocks) {
-		connector_bad_edid(connector, (u8 *)edid, edid->extensions + 1);
+		connector_bad_edid(connector, edid, edid->extensions + 1);
 
 		edid = edid_filter_invalid_blocks(edid, invalid_blocks);
 	}