1 files changed, 74 insertions, 22 deletions

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index cabe32df7cd5..c585da8d6627 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -127,6 +127,9 @@ struct intel_sdvo_priv {
         /* DDC bus used by this SDVO output */
         uint8_t ddc_bus;
 
+        /* Mac mini hack -- use the same DDC as the analog connector */
+        struct i2c_adapter *analog_ddc_bus;
+
         int save_sdvo_mult;
         u16 save_active_outputs;
         struct intel_sdvo_dtd save_input_dtd_1, save_input_dtd_2;
@@ -1496,6 +1499,36 @@ intel_sdvo_multifunc_encoder(struct intel_output *intel_output)
         return (caps > 1);
 }
 
+static struct drm_connector *
+intel_find_analog_connector(struct drm_device *dev)
+{
+        struct drm_connector *connector;
+        struct intel_output *intel_output;
+
+        list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+                intel_output = to_intel_output(connector);
+                if (intel_output->type == INTEL_OUTPUT_ANALOG)
+                        return connector;
+        }
+        return NULL;
+}
+
+static int
+intel_analog_is_connected(struct drm_device *dev)
+{
+        struct drm_connector *analog_connector;
+        analog_connector = intel_find_analog_connector(dev);
+
+        if (!analog_connector)
+                return false;
+
+        if (analog_connector->funcs->detect(analog_connector) ==
+                        connector_status_disconnected)
+                return false;
+
+        return true;
+}
+
 enum drm_connector_status
 intel_sdvo_hdmi_sink_detect(struct drm_connector *connector, u16 response)
 {
@@ -1506,6 +1539,15 @@ intel_sdvo_hdmi_sink_detect(struct drm_connector *connector, u16 response)
 
         edid = drm_get_edid(&intel_output->base,
                             intel_output->ddc_bus);
+
+        /* when there is no edid and no monitor is connected with VGA
+         * port, try to use the CRT ddc to read the EDID for DVI-connector
+         */
+        if (edid == NULL &&
+            sdvo_priv->analog_ddc_bus &&
+            !intel_analog_is_connected(intel_output->base.dev))
+                edid = drm_get_edid(&intel_output->base,
+                                    sdvo_priv->analog_ddc_bus);
         if (edid != NULL) {
                 /* Don't report the output as connected if it's a DVI-I
                  * connector with a non-digital EDID coming out.
@@ -1559,31 +1601,32 @@ static enum drm_connector_status intel_sdvo_detect(struct drm_connector *connect
 static void intel_sdvo_get_ddc_modes(struct drm_connector *connector)
 {
         struct intel_output *intel_output = to_intel_output(connector);
+        struct intel_sdvo_priv *sdvo_priv = intel_output->dev_priv;
+        int num_modes;
 
         /* set the bus switch and get the modes */
-        intel_ddc_get_modes(intel_output);
+        num_modes = intel_ddc_get_modes(intel_output);
 
-#if 0
-        struct drm_device *dev = encoder->dev;
-        struct drm_i915_private *dev_priv = dev->dev_private;
-        /* Mac mini hack.  On this device, I get DDC through the analog, which
-         * load-detects as disconnected.  I fail to DDC through the SDVO DDC,
-         * but it does load-detect as connected.  So, just steal the DDC bits
-         * from analog when we fail at finding it the right way.
+        /*
+         * Mac mini hack.  On this device, the DVI-I connector shares one DDC
+         * link between analog and digital outputs. So, if the regular SDVO
+         * DDC fails, check to see if the analog output is disconnected, in
+         * which case we'll look there for the digital DDC data.
          */
-        crt = xf86_config->output[0];
-        intel_output = crt->driver_private;
-        if (intel_output->type == I830_OUTPUT_ANALOG &&
-            crt->funcs->detect(crt) == XF86OutputStatusDisconnected) {
-                I830I2CInit(pScrn, &intel_output->pDDCBus, GPIOA, "CRTDDC_A");
-                edid_mon = xf86OutputGetEDID(crt, intel_output->pDDCBus);
-                xf86DestroyI2CBusRec(intel_output->pDDCBus, true, true);
-        }
-        if (edid_mon) {
-                xf86OutputSetEDID(output, edid_mon);
-                modes = xf86OutputGetEDIDModes(output);
+        if (num_modes == 0 &&
+            sdvo_priv->analog_ddc_bus &&
+            !intel_analog_is_connected(intel_output->base.dev)) {
+                struct i2c_adapter *digital_ddc_bus;
+
+                /* Switch to the analog ddc bus and try that
+                 */
+                digital_ddc_bus = intel_output->ddc_bus;
+                intel_output->ddc_bus = sdvo_priv->analog_ddc_bus;
+
+                (void) intel_ddc_get_modes(intel_output);
+
+                intel_output->ddc_bus = digital_ddc_bus;
         }
-#endif
 }
 
 /*
@@ -1758,6 +1801,8 @@ static void intel_sdvo_destroy(struct drm_connector *connector)
                 intel_i2c_destroy(intel_output->i2c_bus);
         if (intel_output->ddc_bus)
                 intel_i2c_destroy(intel_output->ddc_bus);
+        if (sdvo_priv->analog_ddc_bus)
+                intel_i2c_destroy(sdvo_priv->analog_ddc_bus);
 
         if (sdvo_priv->sdvo_lvds_fixed_mode != NULL)
                 drm_mode_destroy(connector->dev,
@@ -2177,10 +2222,15 @@ bool intel_sdvo_init(struct drm_device *dev, int output_device)
         }
 
         /* setup the DDC bus. */
-        if (output_device == SDVOB)
+        if (output_device == SDVOB) {
                 intel_output->ddc_bus = intel_i2c_create(dev, GPIOE, "SDVOB DDC BUS");
-        else
+                sdvo_priv->analog_ddc_bus = intel_i2c_create(dev, GPIOA,
+                                                "SDVOB/VGA DDC BUS");
+        } else {
                 intel_output->ddc_bus = intel_i2c_create(dev, GPIOE, "SDVOC DDC BUS");
+                sdvo_priv->analog_ddc_bus = intel_i2c_create(dev, GPIOA,
+                                                "SDVOC/VGA DDC BUS");
+        }
 
         if (intel_output->ddc_bus == NULL)
                 goto err_i2c;
@@ -2248,6 +2298,8 @@ bool intel_sdvo_init(struct drm_device *dev, int output_device)
         return true;
 
 err_i2c:
+        if (sdvo_priv->analog_ddc_bus != NULL)
+                intel_i2c_destroy(sdvo_priv->analog_ddc_bus);
         if (intel_output->ddc_bus != NULL)
                 intel_i2c_destroy(intel_output->ddc_bus);
         if (intel_output->i2c_bus != NULL)