Re: [PATCH 0/3] driver core: generalize driver_override infrastructure

[Gui-Dong Han]

On Mon, Mar 2, 2026 at 6:12 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> On Mon Mar 2, 2026 at 10:41 AM CET, Gui-Dong Han wrote:
> >> Danilo Krummrich (3):
> >>   driver core: generalize driver_override in struct device
> >>   hwmon: axi-fan: don't use driver_override as IRQ name
> >>   driver core: platform: use generic driver_override infrastructure
> >
> > Hi Danilo,
> >
> > It looks like some usages of platform_device->driver_override were
> > missed. I found them here:
> > - drivers/bus/simple-pm-bus.c
> > - drivers/clk/imx/clk-scu.c
> > - drivers/slimbus/qcom-ngd-ctrl.c
> > - sound/soc/samsung/i2s.c
>
> They should all be covered by patch 3, no?

My apologies, I got a bit confused here.

>
> > The good news is these can be easily updated to use the new APIs. This
> > is required to avoid breaking the build, since the field is removed
> > from struct platform_device. The previous build likely passed because
> > these weren't enabled. I will use allyesconfig for testing going
> > forward.
> >
> > I scanned for similar cases and most fit the new APIs perfectly. One
> > exception is drivers/xen/xen-pciback/pci_stub.c. It does
> > strcmp(dev->driver_override, PCISTUB_DRIVER_NAME) instead of using
> > drv->name. We might want to change device_match_driver_override() to
> > take a const char * instead to handle this.
>
> xen_pcibk_pci_driver should use the exact same define, so we can just convert
> this to:
>
> diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
> index e4b27aecbf0591..301207b4a30dac 100644
> --- a/drivers/xen/xen-pciback/pci_stub.c
> +++ b/drivers/xen/xen-pciback/pci_stub.c
> @@ -609,9 +609,9 @@ static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
>
>         match = pcistub_match(dev);
>
> -       if ((dev->driver_override &&
> -            !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) ||
> -           match) {
> +       if (device_match_driver_override(&dev->dev,
> +                                        &xen_pcibk_pci_driver.driver) > 0 ||
> +                                        match) {
>
>                 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
>                     && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
>
> I.e. no separate API needed.

Thanks for the explanation, you are absolutely right.

>
> > Besides axi-fan, I didn't find any other drivers that need to read
> > driver_override. This is great, as it means we hopefully won't need to
> > expose a read API at all.
>
> Great, thanks for checking.