[Intel-gfx] [PATCH] drm/i915: Recognise non-VGA display devices

[Chris Wilson]

Starting with SandyBridge (though possible with earlier hacked BIOSes),
the BIOS may initialise the IGFX as secondary to a discrete GPU. Prior,
it would simply disable the integrated GPU. In such a configuration, the
IGFX is not a primary VGA controller and so should not take part in VGA
arbitration.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_dma.c |   34 +++++++++++++++++++++-------------
 drivers/gpu/drm/i915/i915_drv.c |    2 +-
 drivers/gpu/drm/i915/i915_drv.h |    1 +
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 76f2df7..46ef1fb 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1183,6 +1183,8 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	unsigned long prealloc_size, gtt_size, mappable_size;
 	int ret = 0;
 
+	dev_priv->is_vga = dev->pdev->class == PCI_CLASS_DISPLAY_VGA;
+
 	prealloc_size = dev_priv->mm.gtt->stolen_size;
 	gtt_size = dev_priv->mm.gtt->gtt_total_entries << PAGE_SHIFT;
 	mappable_size = dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT;
@@ -1228,19 +1230,23 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	if (ret)
 		DRM_INFO("failed to find VBIOS tables\n");
 
-	/* if we have > 1 VGA cards, then disable the radeon VGA resources */
-	ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
-	if (ret)
-		goto cleanup_ringbuffer;
+	if (dev_priv->is_vga) {
+		/* If we have > 1 VGA cards with a single output,
+		 * then disable the radeon VGA resources.
+		 */
+		ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
+		if (ret)
+			goto cleanup_ringbuffer;
 
-	intel_register_dsm_handler();
+		intel_register_dsm_handler();
 
-	ret = vga_switcheroo_register_client(dev->pdev,
-					     i915_switcheroo_set_state,
-					     NULL,
-					     i915_switcheroo_can_switch);
-	if (ret)
-		goto cleanup_vga_client;
+		ret = vga_switcheroo_register_client(dev->pdev,
+						     i915_switcheroo_set_state,
+						     NULL,
+						     i915_switcheroo_can_switch);
+		if (ret)
+			goto cleanup_vga_client;
+	}
 
 	/* IIR "flip pending" bit means done if this bit is set */
 	if (IS_GEN3(dev) && (I915_READ(ECOSKPD) & ECO_FLIP_DONE))
@@ -2106,8 +2112,10 @@ int i915_driver_unload(struct drm_device *dev)
 			dev_priv->child_dev_num = 0;
 		}
 
-		vga_switcheroo_unregister_client(dev->pdev);
-		vga_client_register(dev->pdev, NULL, NULL, NULL);
+		if (dev_priv->is_vga) {
+			vga_switcheroo_unregister_client(dev->pdev);
+			vga_client_register(dev->pdev, NULL, NULL, NULL);
+		}
 	}
 
 	/* Free error state after interrupts are fully disabled. */
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 2d31f5f..7fbb132 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -60,7 +60,7 @@ extern int intel_agp_enabled;
 
 #define INTEL_VGA_DEVICE(id, info) {		\
 	.class = PCI_CLASS_DISPLAY_VGA << 8,	\
-	.class_mask = 0xffff00,			\
+	.class_mask = 0xff0000,			\
 	.vendor = 0x8086,			\
 	.device = id,				\
 	.subvendor = PCI_ANY_ID,		\
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 52ceae5..2b274f4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -262,6 +262,7 @@ typedef struct drm_i915_private {
 
 	int has_gem;
 	int relative_constants_mode;
+	int is_vga;
 
 	void __iomem *regs;
 
-- 
1.7.2.3