Messages in this thread |  | | Date | Fri, 13 Mar 2015 10:09:19 +0800 | | From | Fam Zheng <> | | Subject | Re: [RFC PATCH] PCI: Disable MSI/MSI-X only if device is shutdown |
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On Thu, 03/12 19:56, Bandan Das wrote: > Hi Fam, > > Fam Zheng <famz@redhat.com> writes: > > > If the device doesn't support shutdown, disabling interrupts may cause > > trouble. For example, virtio-scsi-pci doesn't implement shutdown, and > > after we disable MSI-X, futher notifications from device will be > > delivered to IRQ, which is unexpected. This IRQ will not be cleared, and > > may prevent us from making progress, by keep triggering interrupts. > > > > Signed-off-by: Fam Zheng <famz@redhat.com> > > --- > > drivers/pci/pci-driver.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > > index 3cb2210..fb29c96 100644 > > --- a/drivers/pci/pci-driver.c > > +++ b/drivers/pci/pci-driver.c > > @@ -448,10 +448,11 @@ static void pci_device_shutdown(struct device *dev) > > > > pm_runtime_resume(dev); > > > > - if (drv && drv->shutdown) > > + if (drv && drv->shutdown) { > > drv->shutdown(pci_dev); > > - pci_msi_shutdown(pci_dev); > > - pci_msix_shutdown(pci_dev); > > + pci_msi_shutdown(pci_dev); > > + pci_msix_shutdown(pci_dev); > > + } > > If the driver doesn't provide a shutdown method and doesn't itself > disable MSI/MSI-X, then pci_msi(x)_shutdown won't be called anymore, > no ?
Right.
> > This is probably ok (but unclean) for a system shutdown, but could > cause problems for something like kexec ?
Doesn't the reset in kexec clean this up during initialization?
Without shutdown, anything in the driver is unclean anyway, for example free_irq is not called.
Fam
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