diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/pci.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 602eb4223510..123408e5a1d6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3414,6 +3414,29 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev) } EXPORT_SYMBOL(pci_wait_for_pending_transaction); +/* + * We should only need to wait 100ms after FLR, but some devices take longer. + * Wait for up to 1000ms for config space to return something other than -1. + * Intel IGD requires this when an LCD panel is attached. We read the 2nd + * dword because VFs don't implement the 1st dword. + */ +static void pci_flr_wait(struct pci_dev *dev) +{ + int i = 0; + u32 id; + + do { + msleep(100); + pci_read_config_dword(dev, PCI_COMMAND, &id); + } while (i++ < 10 && id == ~0); + + if (id == ~0) + dev_warn(&dev->dev, "Failed to return from FLR\n"); + else if (i > 1) + dev_info(&dev->dev, "Required additional %dms to return from FLR\n", + (i - 1) * 100); +} + static int pcie_flr(struct pci_dev *dev, int probe) { u32 cap; @@ -3429,7 +3452,7 @@ static int pcie_flr(struct pci_dev *dev, int probe) 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); - msleep(100); + pci_flr_wait(dev); return 0; } @@ -3459,7 +3482,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe) dev_err(&dev->dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n"); pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR); - msleep(100); + pci_flr_wait(dev); return 0; } |