Re: [PATCH v6 00/11] PCI: Drop duplicated tracking of a pci_dev's bound driver

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Wed, Oct 13, 2021 at 2:33 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> On Mon, Oct 04, 2021 at 02:59:24PM +0200, Uwe Kleine-König wrote:

> I split some of the bigger patches apart so they only touched one
> driver or subsystem at a time.  I also updated to_pci_driver() so it
> returns NULL when given NULL, which makes some of the validations
> quite a bit simpler, especially in the PM code in pci-driver.c.

It's a bit unusual. Other to_*_dev() are not NULL-aware IIRC.

Below are some comments as well.

...

>  static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned 
> short device)
>  {
> +       struct pci_driver *drv = to_pci_driver(pdev->dev.driver);
>         const struct pci_device_id *id;
>
>         if (pdev->vendor == vendor && pdev->device == device)
>                 return true;

> +       for (id = drv ? drv->id_table : NULL; id && id->vendor; id++)
> +               if (id->vendor == vendor && id->device == device)

> +                       break;

return true;

>         return id && id->vendor;

return false;

>  }

...

> +                       afu_result = err_handler->error_detected(afu_dev,
> +                                                                state);

One line?

...

>         device_lock(&vf_dev->dev);
> -       if (vf_dev->dev.driver) {
> +       if (to_pci_driver(vf_dev->dev.driver)) {

Hmm...

...

> +               if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0

> +                   && pci_dev->current_state != PCI_UNKNOWN) {

Can we keep && on the previous line?

> +                       pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
> +                                     "PCI PM: Device state not saved by 
> %pS\n",
> +                                     drv->suspend);
>                 }

...

> +       return drv && drv->resume ?
> +                       drv->resume(pci_dev) : 
> pci_pm_reenable_device(pci_dev);

One line?

...

> +       struct pci_driver *drv = to_pci_driver(dev->dev.driver);
>         const struct pci_error_handlers *err_handler =
> -                       dev->dev.driver ? 
> to_pci_driver(dev->dev.driver)->err_handler : NULL;
> +                       drv ? drv->err_handler : NULL;

Isn't dev->driver == to_pci_driver(dev->dev.driver)?

...

> +       struct pci_driver *drv = to_pci_driver(dev->dev.driver);
>         const struct pci_error_handlers *err_handler =
> -                       dev->dev.driver ? 
> to_pci_driver(dev->dev.driver)->err_handler : NULL;
> +                       drv ? drv->err_handler : NULL;

Ditto.

...

>         device_lock(&dev->dev);
> +       pdrv = to_pci_driver(dev->dev.driver);
>         if (!pci_dev_set_io_state(dev, state) ||
> -               !dev->dev.driver ||
> -               !(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||

> +               !pdrv ||
> +               !pdrv->err_handler ||

One line now?

>                 !pdrv->err_handler->error_detected) {

Or this and the previous line?

...

> +       pdrv = to_pci_driver(dev->dev.driver);
> +       if (!pdrv ||
> +               !pdrv->err_handler ||
>                 !pdrv->err_handler->mmio_enabled)
>                 goto out;

Ditto.

...

> +       pdrv = to_pci_driver(dev->dev.driver);
> +       if (!pdrv ||
> +               !pdrv->err_handler ||
>                 !pdrv->err_handler->slot_reset)
>                 goto out;

Ditto.

...

>         if (!pci_dev_set_io_state(dev, pci_channel_io_normal) ||
> -               !dev->dev.driver ||
> -               !(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||
> +               !pdrv ||
> +               !pdrv->err_handler ||
>                 !pdrv->err_handler->resume)
>                 goto out;

Ditto.

> -       result = PCI_ERS_RESULT_NONE;
>
>         pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
>         if (!pcidev || !pcidev->dev.driver) {
>                 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
>                 pci_dev_put(pcidev);
> -               return result;
> +               return PCI_ERS_RESULT_NONE;
>         }
>         pdrv = to_pci_driver(pcidev->dev.driver);

What about splitting the conditional to two with clear error message
in each and use pci_err() in the second one?

...

>                 default:
>                         dev_err(&pdev->xdev->dev,
> -                               "bad request in aer recovery "
> -                               "operation!\n");
> +                               "bad request in AER recovery operation!\n");

Stray change? Or is it in a separate patch in your tree?

-- 
With Best Regards,
Andy Shevchenko