1 files changed, 41 insertions, 9 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index fd94dbca33ac..58f342659cc7 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -595,6 +595,34 @@ bool radeon_combios_get_clock_info(struct drm_device *dev)
         return false;
 }
 
+static const uint32_t default_primarydac_adj[CHIP_LAST] = {
+        0x00000808,             /* r100  */
+        0x00000808,             /* rv100 */
+        0x00000808,             /* rs100 */
+        0x00000808,             /* rv200 */
+        0x00000808,             /* rs200 */
+        0x00000808,             /* r200  */
+        0x00000808,             /* rv250 */
+        0x00000000,             /* rs300 */
+        0x00000808,             /* rv280 */
+        0x00000808,             /* r300  */
+        0x00000808,             /* r350  */
+        0x00000808,             /* rv350 */
+        0x00000808,             /* rv380 */
+        0x00000808,             /* r420  */
+        0x00000808,             /* r423  */
+        0x00000808,             /* rv410 */
+        0x00000000,             /* rs400 */
+        0x00000000,             /* rs480 */
+};
+
+static void radeon_legacy_get_primary_dac_info_from_table(struct radeon_device *rdev,
+                                                          struct radeon_encoder_primary_dac *p_dac)
+{
+        p_dac->ps2_pdac_adj = default_primarydac_adj[rdev->family];
+        return;
+}
+
 struct radeon_encoder_primary_dac *radeon_combios_get_primary_dac_info(struct
                                                                        radeon_encoder
                                                                        *encoder)
@@ -604,20 +632,20 @@ struct radeon_encoder_primary_dac *radeon_combios_get_primary_dac_info(struct
         uint16_t dac_info;
         uint8_t rev, bg, dac;
         struct radeon_encoder_primary_dac *p_dac = NULL;
+        int found = 0;
 
-        if (rdev->bios == NULL)
+        p_dac = kzalloc(sizeof(struct radeon_encoder_primary_dac),
+                        GFP_KERNEL);
+
+        if (!p_dac)
                 return NULL;
 
+        if (rdev->bios == NULL)
+                goto out;
+
         /* check CRT table */
         dac_info = combios_get_table_offset(dev, COMBIOS_CRT_INFO_TABLE);
         if (dac_info) {
-                p_dac =
-                    kzalloc(sizeof(struct radeon_encoder_primary_dac),
-                            GFP_KERNEL);
-
-                if (!p_dac)
-                        return NULL;
-
                 rev = RBIOS8(dac_info) & 0x3;
                 if (rev < 2) {
                         bg = RBIOS8(dac_info + 0x2) & 0xf;
@@ -628,9 +656,13 @@ struct radeon_encoder_primary_dac *radeon_combios_get_primary_dac_info(struct
                         dac = RBIOS8(dac_info + 0x3) & 0xf;
                         p_dac->ps2_pdac_adj = (bg << 8) | (dac);
                 }
-
+                found = 1;
         }
 
+out:
+        if (!found) /* fallback to defaults */
+                radeon_legacy_get_primary_dac_info_from_table(rdev, p_dac);
+
         return p_dac;
 }