drm/radeon/kms: adjust quirk for acer laptop

Acer laptop (TravelMate 5730G) has an HDMI connector
on the laptop and a DVI connector on the docking station
and both share the same encoder, hpd pin, and ddc line.
The bios connector table reflects this and is technically
correct, however, we drop the DVI connector here since
xrandr has no concept of encoders (only crtcs and connectors)
and will try and drive both connectors with different crtcs
which isn't possible on the hardware side and leaves no crtcs
for LVDS or VGA.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=32732

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -313,7 +313,6 @@ static bool radeon_atom_apply_quirks(struct drm_device *dev,
 				     uint16_t *line_mux,
 				     struct radeon_hpd *hpd)
 {
-	struct radeon_device *rdev = dev->dev_private;
 
 	/* Asus M2A-VM HDMI board lists the DVI port as HDMI */
 	if ((dev->pdev->device == 0x791e) &&
@@ -425,21 +424,23 @@ static bool radeon_atom_apply_quirks(struct drm_device *dev,
 		}
 	}
 
-	/* Acer laptop reports DVI-D as DVI-I and hpd pins reversed */
+	/* Acer laptop (Acer TravelMate 5730G) has an HDMI port
+	 * on the laptop and a DVI port on the docking station and
+	 * both share the same encoder, hpd pin, and ddc line.
+	 * So while the bios table is technically correct,
+	 * we drop the DVI port here since xrandr has no concept of
+	 * encoders and will try and drive both connectors
+	 * with different crtcs which isn't possible on the hardware
+	 * side and leaves no crtcs for LVDS or VGA.
+	 */
 	if ((dev->pdev->device == 0x95c4) &&
 	    (dev->pdev->subsystem_vendor == 0x1025) &&
 	    (dev->pdev->subsystem_device == 0x013c)) {
-		struct radeon_gpio_rec gpio;
-
 		if ((*connector_type == DRM_MODE_CONNECTOR_DVII) &&
 		    (supported_device == ATOM_DEVICE_DFP1_SUPPORT)) {
-			gpio = radeon_lookup_gpio(rdev, 6);
-			*hpd = radeon_atom_get_hpd_info_from_gpio(rdev, &gpio);
+			/* actually it's a DVI-D port not DVI-I */
 			*connector_type = DRM_MODE_CONNECTOR_DVID;
-		} else if ((*connector_type == DRM_MODE_CONNECTOR_HDMIA) &&
-			   (supported_device == ATOM_DEVICE_DFP1_SUPPORT)) {
-			gpio = radeon_lookup_gpio(rdev, 7);
-			*hpd = radeon_atom_get_hpd_info_from_gpio(rdev, &gpio);
+			return false;
 		}
 	}