Re: [PATCH] pci: Don't call resume callback for nearly bound devices

Robert Święcki
2021-11-08T21:37:02Z

Hi all,

> > Here's the call tree:
> >
> > really_probe
> > dev->driver = drv; # <--
> > call_driver_probe
> > dev->bus->probe
> > pci_device_probe
> > __pci_device_probe
> > pci_call_probe
> > local_pci_probe
> > pm_runtime_get_sync
> > ...
> > pci_pm_runtime_resume
> > - if (!pci_dev->driver) # 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of pci_dev->driver")
> > + if (!to_pci_driver(dev->driver))
> > return 0
> > pm->runtime_resume
> > i2c_dw_pci_resume
> > i_dev->init() # <-- NULL ptr deref
> > - pci_dev->driver = pci_drv # b5f9c644eb1b ("PCI: Remove struct pci_dev->driver")
> > pci_drv->probe
> > i2c_dw_pci_probe
>
> I think this analysis is right.
>
> I didn't test this patch, @Robert, maybe you can do this?
>
> Best regards
> Uwe
>
> drivers/pci/pci-driver.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 1d98c974381c..202533654012 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -1299,7 +1299,7 @@ static int pci_pm_runtime_resume(struct device *dev)
> */
> pci_restore_standard_config(pci_dev);
>
> - if (!to_pci_driver(dev->driver))
> + if (!device_is_bound(dev))
> return 0;
>
> pci_fixup_device(pci_fixup_resume_early, pci_dev);

Yes, that fixes it. Thanks for the patch.