[RFC PATCH] PCI: Disable MSI/MSI-X only if device is shutdown

From: Fam Zheng
Date: Thu Mar 12 2015 - 01:21:37 EST

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@xxxxxxxxxx>
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)


- if (drv && drv->shutdown)
+ if (drv && drv->shutdown) {
- pci_msi_shutdown(pci_dev);
- pci_msix_shutdown(pci_dev);
+ pci_msi_shutdown(pci_dev);
+ pci_msix_shutdown(pci_dev);
+ }


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