openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

drm/edid: Don't parse garbage as DispID blocks 

Currently the code assumes that the entire EDID extesion block
can be taken up by the DispID blocks. That is not true. There
is at least always the DispID checksum, and potentially fill
bytes if the extension block uses the interior fill scheme
to pad out to fill EDID block size.

So let's not parse the checksum or the fill bytes as DispID
blocks by having drm_find_displayid_extension() return the
actual length of the DispID data to the caller.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313162054.16009-7-ville.syrjala@linux.intel.com
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Ville Syrjälä 2020-03-13 18:20:51 +02:00
parent ea0aa608a8
commit 8e88c75245
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/gpu/drm/drm_edid.c
View File

@ -3216,6 +3216,7 @@ static u8 *drm_find_displayid_extension(const struct edid *edid,
int *length, int *idx)
{
u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT);
struct displayid_hdr *base;
int ret;
if (!displayid)
@ -3228,6 +3229,9 @@ static u8 *drm_find_displayid_extension(const struct edid *edid,
if (ret)
return NULL;
base = (struct displayid_hdr *)&displayid[*idx];
*length = *idx + sizeof(*base) + base->bytes;
return displayid;
}