Messages in this thread | | | Date | Sat, 31 Jul 2021 14:05:15 +0200 | From | Uwe Kleine-König <> | Subject | Re: [PATCH 1/5] nubus: Simplify check in remove callback |
| |
Hello Finn,
On Sat, Jul 31, 2021 at 08:32:38PM +1000, Finn Thain wrote: > On Tue, 27 Jul 2021, Uwe Kleine-König wrote: > > On Tue, Jul 27, 2021 at 07:50:39PM +1000, Finn Thain wrote: > > > On Tue, 27 Jul 2021, Uwe Kleine-König wrote: > > > > > > > The driver core only calls a remove callback when the device was > > > > successfully bound (aka probed) before. So dev->driver is never > > > > NULL. > > > > > > Are you sure dev->driver is non-NULL for the lifetime of the device? A > > > quick glance at device_reprobe() makes me wonder about that. > > > > Not for the lifetime of the device, but as long as a driver is bound to > > the device. device_reprobe() calls device_driver_detach() after which > > the driver is considered unbound and dev->driver is assigned NULL. (via > > device_driver_detach -> device_release_driver_internal -> > > __device_release_driver) > > Are you saying that this situation does not presently apply to nubus, > zorro or superhyway? Or are you saying that the remove callback will never > be called in this situation?
I'm saying that if you call device_reprobe() the remove callback is called before dev->driver becomes NULL. So in the remove callback it's safe to assume that dev->driver is non-NULL.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [unhandled content-type:application/pgp-signature] | |