[Intel-gfx] [PATCH 2/3] drm/i915: disable drm agp support for !gen3 with kms enabled

[Daniel Vetter]

This is the quick&dirty way Dave Airlie suggested to workaround the
midlayer drm agp brain-damange. Note that i915_probe is only called
when the driver has ksm enabled, so no need to check for that.

We also need to move the intel_agp_enabled check at the right place.
Note that the only thing this does is enforce the correct module load
order (by using a symbol from intel-agp.ko) to ensure that the fake
agp driver is ready before the drm core tries to set up the agp stuff.

Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_drv.c |   18 ++++++++++++------
 1 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a378c08..5223ac2 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -930,10 +930,12 @@ int i915_reset(struct drm_device *dev)
 	return 0;
 }
 
-
 static int __devinit
 i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
+	struct intel_device_info *intel_info =
+		(struct intel_device_info *) ent->driver_data;
+
 	/* Only bind to function 0 of the device. Early generations
 	 * used function 1 as a placeholder for multi-head. This causes
 	 * us confusion instead, especially on the systems where both
@@ -942,6 +944,15 @@ i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (PCI_FUNC(pdev->devfn))
 		return -ENODEV;
 
+	/* Only enable AGP support for gen 3. */
+	if (intel_info->gen != 3) {
+		driver.driver_features &=
+			~(DRIVER_USE_AGP | DRIVER_REQUIRE_AGP);
+	} else if (!intel_agp_enabled) {
+		DRM_ERROR("drm/i915 can't work without intel_agp module!\n");
+		return -ENODEV;
+	}
+
 	return drm_get_pci_dev(pdev, ent, &driver);
 }
 
@@ -1102,11 +1113,6 @@ static struct pci_driver i915_pci_driver = {
 
 static int __init i915_init(void)
 {
-	if (!intel_agp_enabled) {
-		DRM_ERROR("drm/i915 can't work without intel_agp module!\n");
-		return -ENODEV;
-	}
-
 	driver.num_ioctls = i915_max_ioctl;
 
 	/*
-- 
1.7.7.6