From 08e3ed12ca8615b078ea19488fb45b084e5de16b Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Sun, 11 Jun 2023 18:20:06 +0100 Subject: [PATCH] PCI: Add failed link recovery for device reset events Request failed link recovery with any upstream PCIe bridge where a device has not come back after reset within PCI_RESET_WAIT time. Reset the polling interval if recovery succeeded, otherwise continue as usual. [bhelgaas: inline pcie_parent_link_retrain()] Link: https://lore.kernel.org/r/alpine.DEB.2.21.2306111631050.64925@angie.orcam.me.uk Signed-off-by: Maciej W. Rozycki Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f599d321c881e..64f1a87902d89 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1156,7 +1156,14 @@ void pci_resume_bus(struct pci_bus *bus) static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) { int delay = 1; - u32 id; + bool retrain = false; + struct pci_dev *bridge; + + if (pci_is_pcie(dev)) { + bridge = pci_upstream_bridge(dev); + if (bridge) + retrain = true; + } /* * After reset, the device should not silently discard config @@ -1170,21 +1177,33 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) * Command register instead of Vendor ID so we don't have to * contend with the CRS SV value. */ - pci_read_config_dword(dev, PCI_COMMAND, &id); - while (PCI_POSSIBLE_ERROR(id)) { + for (;;) { + u32 id; + + pci_read_config_dword(dev, PCI_COMMAND, &id); + if (!PCI_POSSIBLE_ERROR(id)) + break; + if (delay > timeout) { pci_warn(dev, "not ready %dms after %s; giving up\n", delay - 1, reset_type); return -ENOTTY; } - if (delay > PCI_RESET_WAIT) + if (delay > PCI_RESET_WAIT) { + if (retrain) { + retrain = false; + if (pcie_failed_link_retrain(bridge)) { + delay = 1; + continue; + } + } pci_info(dev, "not ready %dms after %s; waiting\n", delay - 1, reset_type); + } msleep(delay); delay *= 2; - pci_read_config_dword(dev, PCI_COMMAND, &id); } if (delay > PCI_RESET_WAIT) -- 2.30.2