drm/radeon/kms: add additional quirk for Acer rv620 laptop

HPD pins are reversed

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=29387

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index dc9102f..a416ab5 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -268,6 +268,7 @@
 				     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) &&
@@ -370,13 +371,22 @@
 		}
 	}
 
-	/* Acer laptop reports DVI-D as DVI-I */
+	/* Acer laptop reports DVI-D as DVI-I and hpd pins reversed */
 	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))
+		    (supported_device == ATOM_DEVICE_DFP1_SUPPORT)) {
+			gpio = radeon_lookup_gpio(rdev, 6);
+			*hpd = radeon_atom_get_hpd_info_from_gpio(rdev, &gpio);
 			*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);
+		}
 	}
 
 	/* XFX Pine Group device rv730 reports no VGA DDC lines