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authorThomas Reim <reimth@gmail.com>2011-07-29 14:28:57 +0000
committerDave Airlie <airlied@redhat.com>2011-08-04 14:39:35 +0100
commit051963d4832ed61e5ae74f5330b0a94489e101b9 (patch)
tree4ade8f3af4f6ec99d8f76048707072708f5877e7 /drivers/gpu
parent5037f8acf448dd0de9868dc7410f45879d3d1a1b (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.c24
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 7496d245f28..7425e5c9bd7 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");