6.6-stable review patch. If anyone has any objections, please let me know.
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From: Alex Deucher alexander.deucher@amd.com
[ Upstream commit 17c6baff3d5f65c8da164137a58742541a060b2f ]
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@weissschuh.net Reported-by: Thomas Weißschuh linux@weissschuh.net Link: https://lists.freedesktop.org/archives/amd-gfx/2024-June/109964.html Fixes: c324acd5032f ("drm/radeon/kms: parse the extended LCD info block") Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/radeon/radeon_atombios.c | 29 +++++++++++++----------- 1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c index 061396e7fa0f9..53c7273eb6a5c 100644 --- a/drivers/gpu/drm/radeon/radeon_atombios.c +++ b/drivers/gpu/drm/radeon/radeon_atombios.c @@ -1716,26 +1716,29 @@ struct radeon_encoder_atom_dig *radeon_atombios_get_lvds_info(struct 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)) { rdev->mode_info.bios_hardcoded_edid = edid; rdev->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;