From 99e6fbffc973fb0f9074265f80951f61a802792c Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 17 Oct 2011 11:46:06 -0700 Subject: PCI: msi: Disable msi interrupts when we initialize a pci device commit a776c491ca5e38c26d9f66923ff574d041e747f4 upstream. I traced a nasty kexec on panic boot failure to the fact that we had screaming msi interrupts and we were not disabling the msi messages at kernel startup. The booting kernel had not enabled those interupts so was not prepared to handle them. I can see no reason why we would ever want to leave the msi interrupts enabled at boot if something else has enabled those interrupts. The pci spec specifies that msi interrupts should be off by default. Drivers are expected to enable the msi interrupts if they want to use them. Our interrupt handling code reprograms the interrupt handlers at boot and will not be be able to do anything useful with an unexpected interrupt. This patch applies cleanly all of the way back to 2.6.32 where I noticed the problem. Signed-off-by: Eric W. Biederman Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/pci/msi.c') diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 2f10328bf661..e1749825008d 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -869,5 +869,15 @@ EXPORT_SYMBOL(pci_msi_enabled); void pci_msi_init_pci_dev(struct pci_dev *dev) { + int pos; INIT_LIST_HEAD(&dev->msi_list); + + /* Disable the msi hardware to avoid screaming interrupts + * during boot. This is the power on reset default so + * usually this should be a noop. + */ + pos = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (pos) + msi_set_enable(dev, pos, 0); + msix_set_enable(dev, 0); } -- cgit v1.2.3