drm/edid: shorten log output in case of all zeroes edid block

There is no need to dump the whole EDID block in case it contains no
information. Just print a single line stating the block is empty instead
of 8 lines containing only zeroes.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_edid.c

@@ -1088,10 +1088,14 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 
 bad:
 	if (print_bad_edid) {
+		if (drm_edid_is_zero(raw_edid, EDID_LENGTH)) {
+			printk(KERN_ERR "EDID block is all zeroes\n");
+		} else {
 			printk(KERN_ERR "Raw EDID:\n");
 			print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
 			       raw_edid, EDID_LENGTH, false);
 		}
+	}
 	return false;
 }
 EXPORT_SYMBOL(drm_edid_block_valid);