diff options
| author | Thomas Reim <reimth@gmail.com> | 2011-07-29 14:28:57 +0000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2011-08-04 14:39:35 +0100 |
| commit | 051963d4832ed61e5ae74f5330b0a94489e101b9 (patch) | |
| tree | 4ade8f3af4f6ec99d8f76048707072708f5877e7 /drivers/gpu | |
| parent | 5037f8acf448dd0de9868dc7410f45879d3d1a1b (diff) | |
drm: Separate EDID Header Check from EDID Block Check
Provides function drm_edid_header_is_valid() for EDID header check
and replaces EDID header check part of function drm_edid_block_valid()
by a call of drm_edid_header_is_valid().
This is a prerequisite to extend DDC probing, e. g. in function
radeon_ddc_probe() for Radeon devices, by a central EDID header check.
Tested for kernel 2.6.35, 2.6.38 and 3.0
Cc: <stable@kernel.org>
Signed-off-by: Thomas Reim <reimth@gmail.com>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Acked-by: Stephen Michaels <Stephen.Micheals@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_edid.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 7496d245f28c..7425e5c9bd75 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -127,6 +127,23 @@ static const u8 edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 }; + /* + * Sanity check the header of the base EDID block. Return 8 if the header + * is perfect, down to 0 if it's totally wrong. + */ +int drm_edid_header_is_valid(const u8 *raw_edid) +{ + int i, score = 0; + + for (i = 0; i < sizeof(edid_header); i++) + if (raw_edid[i] == edid_header[i]) + score++; + + return score; +} +EXPORT_SYMBOL(drm_edid_header_is_valid); + + /* * Sanity check the EDID block (base or extension). Return 0 if the block * doesn't check out, or 1 if it's valid. @@ -139,12 +156,7 @@ drm_edid_block_valid(u8 *raw_edid) struct edid *edid = (struct edid *)raw_edid; if (raw_edid[0] == 0x00) { - int score = 0; - - for (i = 0; i < sizeof(edid_header); i++) - if (raw_edid[i] == edid_header[i]) - score++; - + int score = drm_edid_header_is_valid(raw_edid); if (score == 8) ; else if (score >= 6) { DRM_DEBUG("Fixing EDID header, your hardware may be failing\n"); |