On Sat, Jun 15, 2024 at 04:09:41PM +0200, Lukas Wunner wrote:
> Below is a small patch which acquires a ref on child. Maybe this
> already does the trick?
Thanks, it appears your idea works! I've run it through 100 test
iterations successfully; previously it would reliably panic within 5 or
fewer iterations.
I also need the first patch from this series, though, otherwise it
inevitably deadlocks. I'd be interested to hear if you have any thoughts
on that one.
Reviewed-by: Keith Busch <kbusch@xxxxxxxxxx>
Tested-by: Keith Busch <kbusch@xxxxxxxxxx>
> -- >8 --
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 2a8063e..82db9a8 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4753,7 +4753,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
> */
> int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
> {
> - struct pci_dev *child;
> + struct pci_dev *child __free(pci_dev_put) = NULL;
> int delay;
>
> if (pci_dev_is_disconnected(dev))
> @@ -4782,8 +4782,9 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
> return 0;
> }
>
> - child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
> - bus_list);
> +
> + child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
> + struct pci_dev, bus_list));
> up_read(&pci_bus_sem);
>
> /*
