On Tue, 20 Jun 2023, Maciej W. Rozycki wrote:
> Export pci_parent_bus_reset() so that drivers do not duplicate it.
> Document the interface.
>
> Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
> ---
> drivers/pci/pci.c | 15 ++++++++++++++-
> include/linux/pci.h | 1 +
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> linux-pci-parent-bus-reset-export.diff
> Index: linux-macro/drivers/pci/pci.c
> ===================================================================
> --- linux-macro.orig/drivers/pci/pci.c
> +++ linux-macro/drivers/pci/pci.c
> @@ -5149,7 +5149,19 @@ int pci_bridge_secondary_bus_reset(struc
> }
> EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
>
> -static int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
> +/**
> + * pci_parent_bus_reset - Reset a device via its upstream PCI bridge
> + * @dev: Device to reset.
> + * @probe: Only check if reset is possible if TRUE, actually reset if FALSE.
> + *
> + * Perform a device reset by requesting a secondary bus reset via the
> + * device's immediate upstream PCI bridge.
> Return 0 if successful or
Kernel doc has Return: section for return values.
> + * -ENOTTY if the reset failed or it could not have been issued in the
> + * first place because the device is not on a secondary bus of any PCI
> + * bridge or it wouldn't be the only device reset. If probing, then
> + * only verify whether it would be possible to issue a reset.
I guess most of the in-depth explanation about reasons why reset
might not me issuable could go into the longer description block.
--
i.
> + */
> +int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
> {
> struct pci_dev *pdev;
>
> @@ -5166,6 +5178,7 @@ static int pci_parent_bus_reset(struct p
>
> return pci_bridge_secondary_bus_reset(dev->bus->self);
> }
> +EXPORT_SYMBOL_GPL(pci_parent_bus_reset);
>
> static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe)
> {
> Index: linux-macro/include/linux/pci.h
> ===================================================================
> --- linux-macro.orig/include/linux/pci.h
> +++ linux-macro/include/linux/pci.h
> @@ -1447,6 +1447,7 @@ int devm_request_pci_bus_resources(struc
>
> /* Temporary until new and working PCI SBR API in place */
> int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
> +int pci_parent_bus_reset(struct pci_dev *dev, bool probe);
>
> #define __pci_bus_for_each_res0(bus, res, ...) \
> for (unsigned int __b = 0; \
>
