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PCI/ERR: Add support for resetting the Root Ports in a platform-specific way

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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 <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Tested-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260729-pci-port-reset-v9-2-53570b92064d@oss.qualcomm.com
This commit is contained in:
Manivannan Sadhasivam 2026-07-29 10:22:28 +05:30 committed by Bjorn Helgaas
parent 3663795872
commit 3fc686d550
3 changed files with 14 additions and 5 deletions
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13
drivers/pci/pci.c
View File

@ -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);
}

5
drivers/pci/pcie/err.c
View File

@ -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);

1
include/linux/pci.h
View File

@ -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 */