On Sat, Aug 15, 2020 at 12:55:57AM +0300, Andy Shevchenko wrote: > On Friday, August 14, 2020, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Fri, Aug 14, 2020 at 09:07:20PM +0300, Andy Shevchenko wrote: > > > On Fri, Aug 14, 2020 at 06:18:16PM +0100, John Garry wrote: > > > > > > diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c > > > > index 4dc443aaef5c..44a8d3644973 100644 > > > > --- a/drivers/usb/core/hcd-pci.c > > > > +++ b/drivers/usb/core/hcd-pci.c > > > > @@ -346,9 +346,9 @@ void usb_hcd_pci_remove(struct pci_dev *dev) > > > > dev_set_drvdata(&dev->dev, NULL); > > > > up_read(&companions_rwsem); > > > > } > > > > - usb_put_hcd(hcd); > > > > if ((hcd->driver->flags & HCD_MASK) < HCD_USB3) > > > > pci_free_irq_vectors(dev); > > > > + usb_put_hcd(hcd); > > > > > > It's not correct approach. > > > We need to copy flags to a temporary variable. > > > I will send a new patch soon to test, thanks! > > > > Just out of curiosity, can you explain what is wrong with John's > > approach? The problem isn't obvious to me. > > > Alloc vector -> create HCD -> put HCD -> free vector > > VS. > > Alloc vector -> create HCD -> free vector -> put HCD > > Of course I might miss something... Sure, the difference in ordering was pretty obvious. What is not obvious is why this should cause a problem. Do you think that the host controller driver is going to try to use the IRQ vector somewhere between the pci_free_irq_vectors call and the usb_put_hcd call? If that's not going to happen then I don't see what difference the order of the two calls makes. Alan Stern
