From 1851617cd2da9cc53cdc1738f4148f4f042c0e56 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 7 May 2015 09:52:21 -0500 Subject: PCI/MSI: Disable MSI at enumeration even if kernel doesn't support MSI If we enable MSI, then kexec a new kernel, the new kernel may receive MSIs it is not prepared for. Commit d5dea7d95c48 ("PCI: msi: Disable msi interrupts when we initialize a pci device") prevents this, but only if the new kernel is built with CONFIG_PCI_MSI=y. Move the "disable MSI" functionality from drivers/pci/msi.c to a new pci_msi_setup_pci_dev() in drivers/pci/probe.c so we can disable MSIs when we enumerate devices even if the kernel doesn't include full MSI support. [bhelgaas: changelog, disable MSIs in pci_setup_device(), put pci_msi_setup_pci_dev() at its final destination] Signed-off-by: Michael S. Tsirkin Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'drivers/pci/probe.c') diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6675a7a1b9fc..a9c5e63049a5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1085,6 +1085,22 @@ int pci_cfg_space_size(struct pci_dev *dev) #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED) +static void pci_msi_setup_pci_dev(struct pci_dev *dev) +{ + /* + * Disable the MSI hardware to avoid screaming interrupts + * during boot. This is the power on reset default so + * usually this should be a noop. + */ + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (dev->msi_cap) + pci_msi_set_enable(dev, 0); + + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (dev->msix_cap) + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); +} + /** * pci_setup_device - fill in class and map information of a device * @dev: the device structure to fill @@ -1140,6 +1156,8 @@ int pci_setup_device(struct pci_dev *dev) /* "Unknown power state" */ dev->current_state = PCI_UNKNOWN; + pci_msi_setup_pci_dev(dev); + /* Early fixups, before probing the BARs */ pci_fixup_device(pci_fixup_early, dev); /* device class may be changed after fixup */ -- cgit v1.2.3