drm/radeon: Properly handle DDC probe for DP bridges

DDC information can be accessed using AUX CH

Fixes failure to probe monitors on some systems with
DP bridge chips.

agd5f: minor fixes

Signed-off-by: Niels Ole Salscheider <niels_ole@salscheider-online.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

4 files changed, 24 insertions, 11 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 47bf162ab9c6..2399f25ec037 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -741,7 +741,7 @@ radeon_vga_detect(struct drm_connector *connector, bool force)
                 ret = connector_status_disconnected;
 
         if (radeon_connector->ddc_bus)
-                dret = radeon_ddc_probe(radeon_connector);
+                dret = radeon_ddc_probe(radeon_connector, false);
         if (dret) {
                 radeon_connector->detected_by_load = false;
                 if (radeon_connector->edid) {
@@ -947,7 +947,7 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
                 return connector->status;
 
         if (radeon_connector->ddc_bus)
-                dret = radeon_ddc_probe(radeon_connector);
+                dret = radeon_ddc_probe(radeon_connector, false);
         if (dret) {
                 radeon_connector->detected_by_load = false;
                 if (radeon_connector->edid) {
@@ -1401,7 +1401,8 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
                 if (encoder) {
                         /* setup ddc on the bridge */
                         radeon_atom_ext_encoder_setup_ddc(encoder);
-                        if (radeon_ddc_probe(radeon_connector)) /* try DDC */
+                        /* bridge chips are always aux */
+                        if (radeon_ddc_probe(radeon_connector, true)) /* try DDC */
                                 ret = connector_status_connected;
                         else if (radeon_connector->dac_load_detect) { /* try load detection */
                                 struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
@@ -1419,7 +1420,8 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
                                 if (radeon_dp_getdpcd(radeon_connector))
                                         ret = connector_status_connected;
                         } else {
-                                if (radeon_ddc_probe(radeon_connector))
+                                /* try non-aux ddc (DP to DVI/HMDI/etc. adapter) */
+                                if (radeon_ddc_probe(radeon_connector, false))
                                         ret = connector_status_connected;
                         }
                 }
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 310c0e5254ba..1da2386d7cf7 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -699,10 +699,15 @@ int radeon_ddc_get_modes(struct radeon_connector *radeon_connector)
         if (radeon_connector->router.ddc_valid)
                 radeon_router_select_ddc_port(radeon_connector);
 
-        if ((radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||
-            (radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) ||
-            (radeon_connector_encoder_get_dp_bridge_encoder_id(&radeon_connector->base) !=
-             ENCODER_OBJECT_ID_NONE)) {
+        if (radeon_connector_encoder_get_dp_bridge_encoder_id(&radeon_connector->base) !=
+            ENCODER_OBJECT_ID_NONE) {
+                struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
+
+                if (dig->dp_i2c_bus)
+                        radeon_connector->edid = drm_get_edid(&radeon_connector->base,
+                                                              &dig->dp_i2c_bus->adapter);
+        } else if ((radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||
+                   (radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_eDP)) {
                 struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
 
                 if ((dig->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT ||
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index c5bddd630eb9..fc60b74ee304 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -39,7 +39,7 @@ extern u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap);
  * radeon_ddc_probe
  *
  */
-bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
+bool radeon_ddc_probe(struct radeon_connector *radeon_connector, bool use_aux)
 {
         u8 out = 0x0;
         u8 buf[8];
@@ -63,7 +63,13 @@ bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
         if (radeon_connector->router.ddc_valid)
                 radeon_router_select_ddc_port(radeon_connector);
 
-        ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
+        if (use_aux) {
+                struct radeon_connector_atom_dig *dig = radeon_connector->con_priv;
+                ret = i2c_transfer(&dig->dp_i2c_bus->adapter, msgs, 2);
+        } else {
+                ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
+        }
+
         if (ret != 2)
                 /* Couldn't find an accessible DDC on this connector */
                 return false;
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index ed8a0fadb6de..4003f5a68c09 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -559,7 +559,7 @@ extern void radeon_i2c_put_byte(struct radeon_i2c_chan *i2c,
                                 u8 val);
 extern void radeon_router_select_ddc_port(struct radeon_connector *radeon_connector);
 extern void radeon_router_select_cd_port(struct radeon_connector *radeon_connector);
-extern bool radeon_ddc_probe(struct radeon_connector *radeon_connector);
+extern bool radeon_ddc_probe(struct radeon_connector *radeon_connector, bool use_aux);
 extern int radeon_ddc_get_modes(struct radeon_connector *radeon_connector);
 
 extern struct drm_encoder *radeon_best_encoder(struct drm_connector *connector);