Messages in this thread | | | Date | Wed, 9 Jul 2014 13:21:12 +0100 | From | David Vrabel <> | Subject | Re: [PATCH v3 2/7] xen/pciback: Don't deadlock when unbinding. |
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On 08/07/14 19:58, konrad@kernel.org wrote: > --- a/drivers/xen/xen-pciback/pci_stub.c > +++ b/drivers/xen/xen-pciback/pci_stub.c > @@ -277,10 +277,15 @@ void pcistub_put_pci_dev(struct pci_dev *dev) > * (so it's ready for the next domain) > */ > > - /* This is OK - we are running from workqueue context > - * and want to inhibit the user from fiddling with 'reset' > + /* We might be holding the PCI lock (see comment at the top of the > + * function) - as such try lock and if we can't then don't worry - > + * as either: > + * - we are 'unbind' in which case 'pcistub_device_release' gets > + * called which does the locked version of this. > + * - the toolstack has the smarts to do it and has done the > + * reset on SysFS before assigning this device to another guest. > */ > - pci_reset_function(dev); > + pci_try_reset_function(dev);
Why not use __pci_reset_function_locked() and ensure all callers of pcistub_put_pci_dev() are holding the device lock?
> pci_restore_state(dev);
If we didn't reset the device there is no need to restore its state.
David
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