drm/i915: Only bind to function 0 of the PCI device (5fe49d86) · Commits · e / devices / android_kernel_fairphone_FP3

Early chipsets (gen2/3) used function 1 as a placeholder for multi-head. We used to ignore these since they were not assigned to PCI_CLASS_DISPLAY_VGA. However with we attempt to bind to all Intel PCI_CLASS_DISPLAY devices (and functions) to work in multi-gpu systems. This fails hard on gen2/3. Reported-by:

Ferenc Wágner <wferi@niif.hu> Tested-by:

Ferenc Wágner <wferi@niif.hu> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28012 Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org

drivers/gpu/drm/i915/i915_drv.c

+8 −0

Original line number	Original line	Diff line number	Diff line
	@@ -568,6 +568,14 @@ int i915_reset(struct drm_device *dev, u8 flags)
	static int __devinit		static int __devinit
	i915_pci_probe(struct pci_dev pdev, const struct pci_device_id ent)		i915_pci_probe(struct pci_dev pdev, const struct pci_device_id ent)
	{		{
			/* 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
			* functions have the same PCI-ID!
			*/
			if (PCI_FUNC(pdev->devfn))
			return -ENODEV;

	return drm_get_pci_dev(pdev, ent, &driver);		return drm_get_pci_dev(pdev, ent, &driver);
	}		}