drm/i915/sdvo: Propagate i2c error from switching DDC control bus.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 18 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 05f5313e14a6..fa9dbb72fb46 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -530,8 +530,8 @@ static int intel_sdvo_get_pixel_multiplier(struct drm_display_mode *mode)
  * another I2C transaction after issuing the DDC bus switch, it will be
  * switched to the internal SDVO register.
  */
-static void intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
-                                              u8 target)
+static int intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
+                                             u8 target)
 {
         u8 out_buf[2], cmd_buf[2], ret_value[2], ret;
         struct i2c_msg msgs[] = {
@@ -557,9 +557,10 @@ static void intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
         };
 
         intel_sdvo_debug_write(intel_sdvo, SDVO_CMD_SET_CONTROL_BUS_SWITCH,
-                                        &target, 1);
+                               &target, 1);
         /* write the DDC switch command argument */
-        intel_sdvo_write_byte(intel_sdvo, SDVO_I2C_ARG_0, target);
+        if (!intel_sdvo_write_byte(intel_sdvo, SDVO_I2C_ARG_0, target))
+                return -EIO;
 
         out_buf[0] = SDVO_I2C_OPCODE;
         out_buf[1] = SDVO_CMD_SET_CONTROL_BUS_SWITCH;
@@ -569,17 +570,20 @@ static void intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
         ret_value[1] = 0;
 
         ret = i2c_transfer(intel_sdvo->base.i2c_bus, msgs, 3);
+        if (ret < 0)
+                return ret;
         if (ret != 3) {
                 /* failure in I2C transfer */
                 DRM_DEBUG_KMS("I2c transfer returned %d\n", ret);
-                return;
+                return -EIO;
         }
         if (ret_value[0] != SDVO_CMD_STATUS_SUCCESS) {
                 DRM_DEBUG_KMS("DDC switch command returns response %d\n",
-                                        ret_value[0]);
-                return;
+                              ret_value[0]);
+                return -EIO;
         }
-        return;
+
+        return 0;
 }
 
 static bool intel_sdvo_set_value(struct intel_sdvo *intel_sdvo, u8 cmd, const void *data, int len)
@@ -1982,13 +1986,18 @@ static int intel_sdvo_master_xfer(struct i2c_adapter *i2c_adap,
 {
         struct intel_sdvo *intel_sdvo;
         const struct i2c_algorithm *algo;
+        int ret;
 
         intel_sdvo = container_of(i2c_adap->algo_data,
                                   struct intel_sdvo,
                                   base);
         algo = intel_sdvo->base.i2c_bus->algo;
 
-        intel_sdvo_set_control_bus_switch(intel_sdvo, intel_sdvo->ddc_bus);
+        ret = intel_sdvo_set_control_bus_switch(intel_sdvo,
+                                                intel_sdvo->ddc_bus);
+        if (ret)
+                return ret;
+
         return algo->master_xfer(i2c_adap, msgs, num);
 }