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. Reported-by: Thomas Weißschuh <li...@weissschuh.net> 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.deuc...@amd.com> --- V2: Incorporate comments. .../gpu/drm/amd/amdgpu/atombios_encoders.c | 29 ++++++++++--------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c index 25feab188dfe..ebf83fee43bb 100644 --- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c +++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c @@ -2065,26 +2065,29 @@ 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; -- 2.45.2
