DRM drivers, at least the vmwgfx driver, when unloaded cause the corresponding PCI device to lose their IRQ. This seems intentional. However, starting with change b4b55cda587442477a3a9f0669e26bba4b7800c0 is the first bad commit commit b4b55cda587442477a3a9f0669e26bba4b7800c0 Author: Jiang Liu <jiang.liu@linux.intel.com> Date: Thu Feb 5 13:44:47 2015 +0800 x86/PCI: Refine the way to release PCI IRQ resources they are not reassigned an IRQ resource on load, and the driver probe fails. What's probably causing this on the driver side is that the driver does not call pci_disable_device() on pci driver remove. Adding such a call in the vmwgfx PCI driver remove() method indeed fixes the issue for vmwgfx, but other drivers are probably broken as well, so think this might require a fix on the x86/pci side. If this behavior is intentional, I think at least a warning is required if a driver removes the pci device driver in this manner. Please see bug discussion at http://lists.freedesktop.org/archives/dri-devel/2015-March/078886.html Thanks, Thomas Hellström
Updating CC / flags.
Hi Thomas, There's a patch "[PATCH] x86/PCI: Fully disable devices before releasing IRQ resource" from Alex Williamson <alex.williamson@redhat.com>, which tries to fix this issue from x86/PCI side. Due to GFW, I can't googling and give a link to that email thread, could you please help to update a link to that thread by google?
(In reply to Jiang Liu from comment #2) > Hi Thomas, > There's a patch "[PATCH] x86/PCI: Fully disable devices before releasing > IRQ resource" from Alex Williamson <alex.williamson@redhat.com>, which tries > to fix this issue from x86/PCI side. > Due to GFW, I can't googling and give a link to that email thread, could > you please help to update a link to that thread by google? Link to patch is here https://lkml.org/lkml/2015/3/5/710