From 3fc686d550f6dba3f4fd53aec173b6dee15e7f98 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Wed, 29 Jul 2026 10:22:28 +0530 Subject: [PATCH] PCI/ERR: Add support for resetting the Root Ports in a platform-specific way Some host bridge devices require resetting the Root Ports in a platform specific way to recover them from error conditions such as Fatal AER errors, Link Down, etc. Introduce pci_host_bridge::reset_root_port() callback and call it from pcibios_reset_secondary_bus() if available. Also, save the Root Port config space before reset and restore it afterwards. The .reset_root_port() callback is responsible for resetting the given Root Port referenced by the 'pci_dev' pointer in a platform-specific way and bring it back to the working state if possible. If any error occurs during the reset operation, relevant errno should be returned. Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Brian Norris Tested-by: Krishna Chaitanya Chundru Tested-by: Richard Zhu Reviewed-by: Frank Li Link: https://patch.msgid.link/20260729-pci-port-reset-v9-2-53570b92064d@oss.qualcomm.com --- drivers/pci/pci.c | 13 +++++++++++++ drivers/pci/pcie/err.c | 5 ----- include/linux/pci.h | 1 + 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 77b17b13ee61..12e099489690 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4841,6 +4841,19 @@ void pci_reset_secondary_bus(struct pci_dev *dev) void __weak pcibios_reset_secondary_bus(struct pci_dev *dev) { + struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); + int ret; + + if (pci_is_root_bus(dev->bus) && host->reset_root_port) { + ret = host->reset_root_port(host, dev); + if (ret) + pci_err(dev, "Failed to reset Root Port: %d\n", ret); + else + pci_restore_state(dev); + + return; + } + pci_reset_secondary_bus(dev); } diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index bebe4bc111d7..13b9d9eb714f 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -256,11 +256,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, } if (status == PCI_ERS_RESULT_NEED_RESET) { - /* - * TODO: Should call platform-specific - * functions to reset slot before calling - * drivers' slot_reset callbacks? - */ status = PCI_ERS_RESULT_RECOVERED; pci_dbg(bridge, "broadcast slot_reset message\n"); pci_walk_bridge(bridge, report_slot_reset, &status); diff --git a/include/linux/pci.h b/include/linux/pci.h index ebb5b9d76360..be82cc0a3371 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -646,6 +646,7 @@ struct pci_host_bridge { void (*release_fn)(struct pci_host_bridge *); int (*enable_device)(struct pci_host_bridge *bridge, struct pci_dev *dev); void (*disable_device)(struct pci_host_bridge *bridge, struct pci_dev *dev); + int (*reset_root_port)(struct pci_host_bridge *bridge, struct pci_dev *dev); void *release_data; unsigned int ignore_reset_delay:1; /* For entire hierarchy */ unsigned int no_ext_tags:1; /* No Extended Tags */