Re: [PATCH 07/18] driver: Add unregister_driver()

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 20.03.23 16:29, Sascha Hauer wrote:
> Registering drivers is one thing, getting rid of them another. Add
> unregister_driver() which is used in the coming USB gadget update.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  drivers/base/driver.c | 16 ++++++++++++++++
>  include/driver.h      |  2 ++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/base/driver.c b/drivers/base/driver.c
> index efbffcdddb..719920ec67 100644
> --- a/drivers/base/driver.c
> +++ b/drivers/base/driver.c
> @@ -405,6 +405,22 @@ int register_driver(struct driver *drv)
>  }
>  EXPORT_SYMBOL(register_driver);
>  
> +void unregister_driver(struct driver *drv)
> +{
> +	struct device *dev;
> +
> +	list_del(&drv->list);
> +	list_del(&drv->bus_list);
> +
> +	bus_for_each_device(drv->bus, dev) {
> +		if (dev->driver == drv) {
> +			drv->bus->remove(dev);

I think drv->bus->remove may be NULL here and you need to guard against that.
While at it, could you switch commands/devunbind.c to use this new function?

Thanks,
Ahmad

> +			dev->driver = NULL;
> +			list_del(&dev->active);
> +		}
> +	}
> +}
> +
>  struct resource *dev_get_resource(struct device *dev, unsigned long type,
>  				  int num)
>  {
> diff --git a/include/driver.h b/include/driver.h
> index 2cf0190699..5605a3db24 100644
> --- a/include/driver.h
> +++ b/include/driver.h
> @@ -137,6 +137,8 @@ struct driver {
>  /* Register devices and drivers.
>   */
>  int register_driver(struct driver *);
> +void unregister_driver(struct driver *drv);
> +
>  int register_device(struct device *);
>  
>  /* manualy probe a device

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