drm/edid: Try harder to fix up base EDID blocks
Requiring the first byte of the EDID base block header to be 0 means we
don't fix up as many transfer errors as we could. Instead have the
callers specify whether it's meant to be block 0 or not, and
conditionally run header fixup based on that.
Bugzilla: https://bugzilla.redhat.com/812890
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index c6366e9..f425379 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -149,13 +149,13 @@
* Sanity check the EDID block (base or extension). Return 0 if the block
* doesn't check out, or 1 if it's valid.
*/
-bool drm_edid_block_valid(u8 *raw_edid)
+bool drm_edid_block_valid(u8 *raw_edid, int block)
{
int i;
u8 csum = 0;
struct edid *edid = (struct edid *)raw_edid;
- if (raw_edid[0] == 0x00) {
+ if (block == 0) {
int score = drm_edid_header_is_valid(raw_edid);
if (score == 8) ;
else if (score >= 6) {
@@ -219,7 +219,7 @@
return false;
for (i = 0; i <= edid->extensions; i++)
- if (!drm_edid_block_valid(raw + i * EDID_LENGTH))
+ if (!drm_edid_block_valid(raw + i * EDID_LENGTH, i))
return false;
return true;
@@ -299,7 +299,7 @@
for (i = 0; i < 4; i++) {
if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
goto out;
- if (drm_edid_block_valid(block))
+ if (drm_edid_block_valid(block, 0))
break;
if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
connector->null_edid_counter++;
@@ -324,7 +324,7 @@
block + (valid_extensions + 1) * EDID_LENGTH,
j, EDID_LENGTH))
goto out;
- if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
+ if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH, j)) {
valid_extensions++;
break;
}