This is a note to let you know that I've just added the patch titled
drm/amdgpu: properly handle vbios fake edid sizing
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amdgpu-properly-handle-vbios-fake-edid-sizing.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5f0cd5bd96b23bdcf29cf4581864aa550a1e2e44
Author: Alex Deucher <alexander.deucher@xxxxxxx>
Date: Tue Jul 23 13:23:56 2024 -0400
drm/amdgpu: properly handle vbios fake edid sizing
[ Upstream commit 8155566a26b8d6c1dd914f06a0c652e4e2f2adf1 ]
The comment in the vbios structure says:
// = 128 means EDID length is 128 bytes, otherwise the EDID length = ucFakeEDIDLength*128
This fake edid struct has not been used in a long time, so I'm
not sure if there were actually any boards out there with a non-128 byte
EDID, but align the code with the comment.
Reviewed-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Reported-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Link: https://lists.freedesktop.org/archives/amd-gfx/2024-June/109964.html
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
index 9de266a1bfbe0..251975697d69d 100644
--- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
@@ -2095,26 +2095,29 @@ amdgpu_atombios_encoder_get_lcd_info(struct amdgpu_encoder *encoder)
fake_edid_record = (ATOM_FAKE_EDID_PATCH_RECORD *)record;
if (fake_edid_record->ucFakeEDIDLength) {
struct edid *edid;
- int edid_size =
- max((int)EDID_LENGTH, (int)fake_edid_record->ucFakeEDIDLength);
- edid = kmalloc(edid_size, GFP_KERNEL);
+ int edid_size;
+
+ if (fake_edid_record->ucFakeEDIDLength == 128)
+ edid_size = fake_edid_record->ucFakeEDIDLength;
+ else
+ edid_size = fake_edid_record->ucFakeEDIDLength * 128;
+ edid = kmemdup(&fake_edid_record->ucFakeEDIDString[0],
+ edid_size, GFP_KERNEL);
if (edid) {
- memcpy((u8 *)edid, (u8 *)&fake_edid_record->ucFakeEDIDString[0],
- fake_edid_record->ucFakeEDIDLength);
-
if (drm_edid_is_valid(edid)) {
adev->mode_info.bios_hardcoded_edid = edid;
adev->mode_info.bios_hardcoded_edid_size = edid_size;
- } else
+ } else {
kfree(edid);
+ }
}
+ record += struct_size(fake_edid_record,
+ ucFakeEDIDString,
+ edid_size);
+ } else {
+ /* empty fake edid record must be 3 bytes long */
+ record += sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1;
}
- record += fake_edid_record->ucFakeEDIDLength ?
- struct_size(fake_edid_record,
- ucFakeEDIDString,
- fake_edid_record->ucFakeEDIDLength) :
- /* empty fake edid record must be 3 bytes long */
- sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1;
break;
case LCD_PANEL_RESOLUTION_RECORD_TYPE:
panel_res_record = (ATOM_PANEL_RESOLUTION_PATCH_RECORD *)record;
