From a2758b6b8fdba5f1045f571fdb39d9bdb8ba0813 Mon Sep 17 00:00:00 2001 From: Sinan Kaya Date: Tue, 27 Feb 2018 14:14:10 -0600 Subject: [PATCH] PCI: Rename pci_flr_wait() to pci_dev_wait() and make it generic PCIe r4.0, sec 2.3.1, Request Handling Rules, says: Valid reset conditions after which a device is permitted to return CRS are: * Cold, Warm, and Hot Resets, * FLR * A reset initiated in response to a D3hot to D0 uninitialized Try to reuse FLR implementation towards other reset types. Signed-off-by: Sinan Kaya Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 48 +++++++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 17 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7aa11b1fbee3..9493b97436c3 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -126,6 +126,9 @@ static int __init pcie_port_pm_setup(char *str) } __setup("pcie_port_pm=", pcie_port_pm_setup); +/* Time to wait after a reset for device to become responsive */ +#define PCIE_RESET_READY_POLL_MS 60000 + /** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search @@ -4017,20 +4020,13 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev) } EXPORT_SYMBOL(pci_wait_for_pending_transaction); -static int pci_flr_wait(struct pci_dev *dev) +static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) { - int delay = 1, timeout = 60000; + int delay = 1; u32 id; /* - * Per PCIe r3.1, sec 6.6.2, a device must complete an FLR within - * 100ms, but may silently discard requests while the FLR is in - * progress. Wait 100ms before trying to access the device. - */ - msleep(100); - - /* - * After 100ms, the device should not silently discard config + * After reset, the device should not silently discard config * requests, but it may still indicate that it needs more time by * responding to them with CRS completions. The Root Port will * generally synthesize ~0 data to complete the read (except when @@ -4044,14 +4040,14 @@ static int pci_flr_wait(struct pci_dev *dev) pci_read_config_dword(dev, PCI_COMMAND, &id); while (id == ~0) { if (delay > timeout) { - pci_warn(dev, "not ready %dms after FLR; giving up\n", - 100 + delay - 1); + pci_warn(dev, "not ready %dms after %s; giving up\n", + delay - 1, reset_type); return -ENOTTY; } if (delay > 1000) - pci_info(dev, "not ready %dms after FLR; waiting\n", - 100 + delay - 1); + pci_info(dev, "not ready %dms after %s; waiting\n", + delay - 1, reset_type); msleep(delay); delay *= 2; @@ -4059,7 +4055,8 @@ static int pci_flr_wait(struct pci_dev *dev) } if (delay > 1000) - pci_info(dev, "ready %dms after FLR\n", 100 + delay - 1); + pci_info(dev, "ready %dms after %s\n", delay - 1, + reset_type); return 0; } @@ -4096,7 +4093,15 @@ int pcie_flr(struct pci_dev *dev) pci_err(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); - return pci_flr_wait(dev); + + /* + * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within + * 100ms, but may silently discard requests while the FLR is in + * progress. Wait 100ms before trying to access the device. + */ + msleep(100); + + return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS); } EXPORT_SYMBOL_GPL(pcie_flr); @@ -4129,7 +4134,16 @@ static int pci_af_flr(struct pci_dev *dev, int probe) pci_err(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); - return pci_flr_wait(dev); + + /* + * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006, + * updated 27 July 2006; a device must complete an FLR within + * 100ms, but may silently discard requests while the FLR is in + * progress. Wait 100ms before trying to access the device. + */ + msleep(100); + + return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS); } /** -- 2.11.0