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| author | Michael S. Tsirkin <mst@redhat.com> | 2015-05-07 16:52:21 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-05-07 16:52:21 +0200 |
| commit | 1851617cd2da9cc53cdc1738f4148f4f042c0e56 (patch) | |
| tree | 2c742020d1c4222bccaceb1cf118fde5eab3c0a7 /drivers/pci/probe.c | |
| parent | PCI/MSI: Export pci_msi_set_enable(), pci_msix_clear_and_set_ctrl() (diff) | |
| download | linux-1851617cd2da9cc53cdc1738f4148f4f042c0e56.tar.xz linux-1851617cd2da9cc53cdc1738f4148f4f042c0e56.zip | |
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 <mst@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 18 |
1 files changed, 18 insertions, 0 deletions
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 */ |