On Tue, Jul 21, 2020 at 01:24:51PM +0200, Lukas Wunner wrote:
> pci_dev_reset_slot_function() refuses to reset a hotplug slot if it is
> shared by multiple pci_devs. That's the case if and only if the slot is
> occupied by a multifunction device.
>
> Simplify the function to check the device's multifunction flag instead
> of iterating over the devices on the bus. (Iterating over the devices
> requires holding pci_bus_sem, which the function erroneously does not
> acquire.)
>
> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Applied to pci/misc for v5.10, thanks!
> ---
> drivers/pci/pci.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 455da72..b406611 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4914,16 +4914,10 @@ static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
>
> static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
> {
> - struct pci_dev *pdev;
> -
> - if (dev->subordinate || !dev->slot ||
> + if (dev->multifunction || dev->subordinate || !dev->slot ||
> dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
> return -ENOTTY;
>
> - list_for_each_entry(pdev, &dev->bus->devices, bus_list)
> - if (pdev != dev && pdev->slot == dev->slot)
> - return -ENOTTY;
> -
> return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
> }
>
> --
> 2.27.0
>
