2 files changed, 41 insertions, 5 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index 2a027e00762a..cb60f5532334 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -863,8 +863,10 @@ struct radeon_encoder_lvds *radeon_combios_get_lvds_info(struct radeon_encoder
         int tmp, i;
         struct radeon_encoder_lvds *lvds = NULL;
 
-        if (rdev->bios == NULL)
-                return radeon_legacy_get_lvds_info_from_regs(rdev);
+        if (rdev->bios == NULL) {
+                lvds = radeon_legacy_get_lvds_info_from_regs(rdev);
+                goto out;
+        }
 
         lcd_info = combios_get_table_offset(dev, COMBIOS_LCD_INFO_TABLE);
 
@@ -965,11 +967,13 @@ struct radeon_encoder_lvds *radeon_combios_get_lvds_info(struct radeon_encoder
                                 lvds->native_mode.flags = 0;
                         }
                 }
-                encoder->native_mode = lvds->native_mode;
         } else {
                 DRM_INFO("No panel info found in BIOS\n");
-                return radeon_legacy_get_lvds_info_from_regs(rdev);
+                lvds = radeon_legacy_get_lvds_info_from_regs(rdev);
         }
+out:
+        if (lvds)
+                encoder->native_mode = lvds->native_mode;
         return lvds;
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index d2842da8c8b0..5ee81b6a8799 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -227,6 +227,36 @@ int radeon_connector_set_property(struct drm_connector *connector, struct drm_pr
         return 0;
 }
 
+static void radeon_fixup_lvds_native_mode(struct drm_encoder *encoder,
+                                          struct drm_connector *connector)
+{
+        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
+        struct radeon_native_mode *native_mode = &radeon_encoder->native_mode;
+
+        /* Try to get native mode details from EDID if necessary */
+        if (!native_mode->dotclock) {
+                struct drm_display_mode *t, *mode;
+
+                list_for_each_entry_safe(mode, t, &connector->probed_modes, head) {
+                        if (mode->hdisplay == native_mode->panel_xres &&
+                            mode->vdisplay == native_mode->panel_yres) {
+                                native_mode->hblank = mode->htotal - mode->hdisplay;
+                                native_mode->hoverplus = mode->hsync_start - mode->hdisplay;
+                                native_mode->hsync_width = mode->hsync_end - mode->hsync_start;
+                                native_mode->vblank = mode->vtotal - mode->vdisplay;
+                                native_mode->voverplus = mode->vsync_start - mode->vdisplay;
+                                native_mode->vsync_width = mode->vsync_end - mode->vsync_start;
+                                native_mode->dotclock = mode->clock;
+                                DRM_INFO("Determined LVDS native mode details from EDID\n");
+                                break;
+                        }
+                }
+        }
+        if (!native_mode->dotclock) {
+                DRM_INFO("No LVDS native mode details, disabling RMX\n");
+                radeon_encoder->rmx_type = RMX_OFF;
+        }
+}
 
 static int radeon_lvds_get_modes(struct drm_connector *connector)
 {
@@ -239,9 +269,11 @@ static int radeon_lvds_get_modes(struct drm_connector *connector)
                 ret = radeon_ddc_get_modes(radeon_connector);
                 if (ret > 0) {
                         encoder = radeon_best_single_encoder(connector);
-                        if (encoder)
+                        if (encoder) {
+                                radeon_fixup_lvds_native_mode(encoder, connector);
                                 /* add scaled modes */
                                 radeon_add_common_modes(encoder, connector);
+                        }
                         return ret;
                 }
         }