diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2363922b3b95..b01bd5bba8e6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3860,24 +3860,41 @@ static void pci_flr_wait(struct pci_dev *dev) (i - 1) * 100); } -static int pcie_flr(struct pci_dev *dev, int probe) +/** + * pcie_has_flr - check if a device supports function level resets + * @dev: device to check + * + * Returns true if the device advertises support for PCIe function level + * resets. + */ +static bool pcie_has_flr(struct pci_dev *dev) { u32 cap; - pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); - if (!(cap & PCI_EXP_DEVCAP_FLR)) - return -ENOTTY; + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) + return false; - if (probe) - return 0; + pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); + return cap & PCI_EXP_DEVCAP_FLR; +} +/** + * pcie_flr - initiate a PCIe function level reset + * @dev: device to reset + * + * Initiate a function level reset on @dev. The caller should ensure the + * device supports FLR before calling this function, e.g. by using the + * pcie_has_flr() helper. + */ +void pcie_flr(struct pci_dev *dev) +{ if (!pci_wait_for_pending_transaction(dev)) dev_err(&dev->dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); pci_flr_wait(dev); - return 0; } +EXPORT_SYMBOL_GPL(pcie_flr); static int pci_af_flr(struct pci_dev *dev, int probe) { @@ -3888,6 +3905,9 @@ static int pci_af_flr(struct pci_dev *dev, int probe) if (!pos) return -ENOTTY; + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) + return -ENOTTY; + pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap); if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) return -ENOTTY; @@ -4058,9 +4078,12 @@ static int __pci_dev_reset(struct pci_dev *dev, int probe) if (rc != -ENOTTY) goto done; - rc = pcie_flr(dev, probe); - if (rc != -ENOTTY) + if (pcie_has_flr(dev)) { + if (!probe) + pcie_flr(dev); + rc = 0; goto done; + } rc = pci_af_flr(dev, probe); if (rc != -ENOTTY) |