From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [RFC PATCH] PCI: Disable MSI/MSI-X only if device is shutdown Date: Thu, 12 Mar 2015 17:21:11 +0100 Message-ID: <5501BCF7.9080004@redhat.com> References: <1426137682-12287-1-git-send-email-famz@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1426137682-12287-1-git-send-email-famz@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Fam Zheng , linux-kernel@vger.kernel.org Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, Linux Virtualization List-Id: virtualization@lists.linuxfoundation.org On 12/03/2015 06:21, Fam Zheng wrote: > 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 > --- > 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); > + } > > #ifdef CONFIG_KEXEC > /* > The patch may be okay, but I think the bug here is also that virtio-pci is not defining a .shutdown callback. It should define one and call free_irq (for INTX) and pci_disable_msix. How is this related to the virtio-scsi patch that you posted? Do you need both to fix the problem you reported? Paolo