drm/edid: new drm_edid_block_checksum helper function V3

The function will also be used by a later patch, so factor it out.

V2: make raw_edid const, define/declare before first use
V3: fix erroneuos removal of csum variable

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>
This commit is contained in:
Stefan Brüns 2014-11-30 19:57:43 +01:00 committed by Daniel Vetter
parent da4c07b727
commit c465bbc87c

View File

@ -1014,6 +1014,16 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
MODULE_PARM_DESC(edid_fixup,
"Minimum number of valid EDID header bytes (0-8, default 6)");
static int drm_edid_block_checksum(const u8 *raw_edid)
{
int i;
u8 csum = 0;
for (i = 0; i < EDID_LENGTH; i++)
csum += raw_edid[i];
return csum;
}
static bool drm_edid_is_zero(const u8 *in_edid, int length)
{
if (memchr_inv(in_edid, 0, length))
@ -1035,8 +1045,7 @@ static bool drm_edid_is_zero(const u8 *in_edid, int length)
*/
bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
{
int i;
u8 csum = 0;
u8 csum;
struct edid *edid = (struct edid *)raw_edid;
if (WARN_ON(!raw_edid))
@ -1056,8 +1065,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
}
}
for (i = 0; i < EDID_LENGTH; i++)
csum += raw_edid[i];
csum = drm_edid_block_checksum(raw_edid);
if (csum) {
if (print_bad_edid) {
DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);