drm/radeon/kms: fix extended lvds info parsing

On rev <= 1.1 tables, the offset is absolute,
on newer tables, it's relative.

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=700326

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index dd881d0..90dfb2b 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -1574,9 +1574,17 @@ struct radeon_encoder_atom_dig *radeon_atombios_get_lvds_info(struct
                        ATOM_FAKE_EDID_PATCH_RECORD *fake_edid_record;
                        ATOM_PANEL_RESOLUTION_PATCH_RECORD *panel_res_record;
                        bool bad_record = false;
-                       u8 *record = (u8 *)(mode_info->atom_context->bios +
-                                           data_offset +
-                                           le16_to_cpu(lvds_info->info.usModePatchTableOffset));
+                       u8 *record;
+
+                       if ((frev == 1) && (crev < 2))
+                               /* absolute */
+                               record = (u8 *)(mode_info->atom_context->bios +
+                                               le16_to_cpu(lvds_info->info.usModePatchTableOffset));
+                       else
+                               /* relative */
+                               record = (u8 *)(mode_info->atom_context->bios +
+                                               data_offset +
+                                               le16_to_cpu(lvds_info->info.usModePatchTableOffset));
                        while (*record != ATOM_RECORD_END_TYPE) {
                                switch (*record) {
                                case LCD_MODE_PATCH_RECORD_MODE_TYPE: