Commit 17c6baff authored by Alex Deucher's avatar Alex Deucher
Browse files

drm/radeon: properly handle vbios fake edid sizing 



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: default avatarThomas Weißschuh <linux@weissschuh.net>
Reported-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Link: https://lists.freedesktop.org/archives/amd-gfx/2024-June/109964.html


Fixes: c324acd5 ("drm/radeon/kms: parse the extended LCD info block")
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8155566a

drivers/gpu/drm/radeon/radeon_atombios.c

+16 −13
Original line number Diff line number Diff line
@@ -1717,26 +1717,29 @@ 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);

						if (edid) {

							memcpy((u8 *)edid, (u8 *)&fake_edid_record->ucFakeEDIDString[0],

							       fake_edid_record->ucFakeEDIDLength);

						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) {

							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 += fake_edid_record->ucFakeEDIDLength ?

						  struct_size(fake_edid_record,

						record += struct_size(fake_edid_record,

								      ucFakeEDIDString,

							      fake_edid_record->ucFakeEDIDLength) :

								      edid_size);

					} else {

						/* empty fake edid record must be 3 bytes long */

						  sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1;

						record += sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1;

					}

					break;

				case LCD_PANEL_RESOLUTION_RECORD_TYPE:

					panel_res_record = (ATOM_PANEL_RESOLUTION_PATCH_RECORD *)record;