On 03/10/2015 10:05 PM, Dave Airlie wrote: > On 10 March 2015 at 22:55, Thomas Hellstrom <thellstrom@xxxxxxxxxx> wrote: >> On 03/09/2015 09:25 PM, Dave Airlie wrote: >>> On 10 March 2015 at 02:02, Thomas Hellstrom <thellstrom@xxxxxxxxxx> wrote: >>>> On 03/09/2015 04:22 PM, Daniel Vetter wrote: >>>>> On Mon, Mar 09, 2015 at 11:04:01AM +0100, Thomas Hellstrom wrote: >>>>>> Hi, >>>>>> >>>>>> I'm not sure this started with 4.0 but when I rmmod the device driver >>>>>> like so >>>>>> rmmod vmwgfx >>>>>> >>>>>> The device loses its IRQ line as shown in lscpi: >>>>>> Flags: bus master, medium devsel, latency 64 <irq missing here> >>>>>> >>>>>> and a subsequent modprobe will fail since pdev->irq is 0. >>>>>> >>>>>> Is anyone else seeing this with other drivers? >>>>> I seen occasionally (over the past couple of kernels) random zeros in pdev >>>>> but dismissed it as broken machines or bugs in i915 (we have them ...). >>>>> Usually the box died chasing a NULL pointer from pdev. Otherwise no. >>>>> -Daniel >>>> OK. Thanks for the info. Since in my case this is 100% reproducible I >>>> guess I have an excellent opportunity to bisect the problem :-/ >>>> >>> does lspci -H1, or some option like to direct access hw show it? >>> >>> just whether this is the kernel copy or the hw register getting messed up. >>> >>> Dave. >> Hi, Dave, >> >> lspci -H1 indeed shows the IRQ number. It turns out that the commit >> introduced in 4.0 breaking this is >> >> b4b55cda587442477a3a9f0669e26bba4b7800c0 is the first bad commit >> commit b4b55cda587442477a3a9f0669e26bba4b7800c0 >> Author: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> >> Date: Thu Feb 5 13:44:47 2015 +0800 >> >> x86/PCI: Refine the way to release PCI IRQ resources >> >> >> It's obvious from the commit message that unloading the driver *should* >> drop the irq resource but its not >> obvious what's reallocating that resource on driver load... >> >> Anyway, it turns out that adding a >> pci_disable_device(pdev) in the pci driver's remove() method >> (vmw_remove() in my case) appears to fix the problem: >> The device irq is removed on driver unload and enabled again on driver >> load There appears to be no pci_disable_device() on driver exit in core drm. > Yes that is because at one time pre kms if you pci disabled the VGA device, > bad things would happen. > > I think with modesetting driver it shouldn't be a problem anymore. > > Dave. So what's the preferred remedy here? should I file a bug against the above commit or should we go ahead modifying the DRM drivers? Thanks, Thomas > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
