On Thu, Oct 16, 2025 at 02:55:28PM +0200, Danilo Krummrich wrote: > The driver model defines the lifetime of the private data stored in (and > owned by) a bus device to be valid from when the driver is bound to a > device (i.e. from successful probe()) until the driver is unbound from > the device. > > This is already taken care of by the Rust implementation of the driver > model. However, we still ask drivers to return a Result<Pin<KBox<Self>>> > from probe(). > > Unlike in C, where we do not have the concept of initializers, but > rather deal with uninitialized memory, drivers can just return an > impl PinInit<Self, Error> instead. > > This contributed to more clarity to the fact that a driver returns it's > device private data in probe() and the Rust driver model owns the data, > manages the lifetime and - considering the lifetime - provides (safe) > accessors for the driver. > > Hence, let probe() functions return an impl PinInit<Self, Error> instead > of Result<Pin<KBox<Self>>>. > > Signed-off-by: Danilo Krummrich <[email protected]> > --- > Depends on a minor pin-init patch [1] (Benno will send it to the list > soon). A branch with this patch and the pin-init dependency is available > in [2]. > > [1] https://github.com/Rust-for-Linux/pin-init/pull/86/commits > [2] > https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=probe_return
Overall LGTM. Reviewed-by: Alice Ryhl <[email protected]> > impl Device<CoreInternal> { > /// Store a pointer to the bound driver's private data. > - pub fn set_drvdata(&self, data: impl ForeignOwnable) { > + pub fn set_drvdata<T: 'static>(&self, data: impl PinInit<T, Error>) -> > Result { > + let data = KBox::pin_init(data, GFP_KERNEL)?; Perhaps the gfp flags should be an argument set_drvdata? Alice
