On Sun, Jun 08, 2025 at 09:54:30AM +0200, Benno Lossin wrote:
> On Fri Jun 6, 2025 at 7:08 PM CEST, Igor Korotin wrote:
> > @@ -141,6 +141,38 @@ pub trait Adapter {
> > /// The type holding driver private data about each device id supported by the driver.
> > type IdInfo: 'static;
> >
> > + /// The [`acpi::IdTable`] of the corresponding driver
> > + fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>>;
> > +
> > + /// Returns the driver's private data from the matching entry in the [`acpi::IdTable`], if any.
> > + ///
> > + /// If this returns `None`, it means there is no match with an entry in the [`acpi::IdTable`].
> > + #[cfg(CONFIG_ACPI)]
> > + fn acpi_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
> > + let table = Self::acpi_id_table()?;
> > +
> > + // SAFETY:
> > + // - `table` has static lifetime, hence it's valid for read,
> > + // - `dev` is guaranteed to be valid while it's alive, and so is `pdev.as_ref().as_raw()`.
> > + let raw_id = unsafe { bindings::acpi_match_device(table.as_ptr(), dev.as_raw()) };
> > +
> > + if raw_id.is_null() {
> > + None
> > + } else {
> > + // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and
> > + // does not add additional invariants, so it's safe to transmute.
> > + let id = unsafe { &*raw_id.cast::<acpi::DeviceId>() };
> > +
> > + Some(table.info(<acpi::DeviceId as crate::device_id::RawDeviceId>::index(id)))
> > + }
> > + }
> > +
> > + #[cfg(not(CONFIG_ACPI))]
> > + #[allow(missing_docs)]
>
> I think we should change this to one single definition and do
>
> if cfg!(not(CONFIG_ACPI)) {
> return None;
> }
> /* body from above */
>
> In a single function instead.
Generally, that's fine, but in this case I'd rather keep it as it is for
consistency with the rest of the file.
> > + fn acpi_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {
> > + None
> > + }
> > +
> > /// The [`of::IdTable`] of the corresponding driver.
> > fn of_id_table() -> Option<of::IdTable<Self::IdInfo>>;
> >
> > @@ -178,6 +210,11 @@ fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {
> > /// If this returns `None`, it means that there is no match in any of the ID tables directly
> > /// associated with a [`device::Device`].
> > fn id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
> > + let id = Self::acpi_id_info(dev);
> > + if id.is_some() {
> > + return id;
> > + }
>
> Is a driver only going to have one id_info? Or is there some kind of
> precedence?
A driver potentially has lots of them, but the device is only matching a single
entry in one of the driver's ID tables and hence a single ID info.
