Re: [cdi-devel] [PATCH v2 5/9] cdi.h: Add cdi_handle_bus_device()

[Kevin Wolf <kevin@xxxxxxxxxx>]

On Thu, Apr 16, 2015 at 12:13:54AM +0200, Max Reitz wrote:
> + Currently, all devices provided on a bus have to be passed to the
>   init_device() function of all drivers handling any device type on that
>   bus. cdi_handle_bus_device() can be used by the driver to specify a
>   pattern (struct cdi_bus_device_pattern) which allows the CDI
>   implementation to speed up the selection of the correct driver for a
>   new device.
> 
> Signed-off-by: Max Reitz <max@xxxxxxxxxx>

As you still haven't convinced me that you only speak Saxionian and no
German, bilingual documentation, please. ;-)

> diff --git a/include/cdi.h b/include/cdi.h
> index 998e080..9c1c1b1 100644
> --- a/include/cdi.h
> +++ b/include/cdi.h
> @@ -141,6 +141,17 @@ struct cdi_bus_data {
>  };
>  
>  /**
> + * This structure, which is extended by any bus type supporting it, contains
> + * information about which devices can be handled by a certain driver.
> + * Typically, it will contain some of the fields provided by the appropriate
> + * cdi_bus_data structure (the ones which are used to identify a device like
> + * device/vendor ID) where negative values signify a "don't care".
> + */
> +struct cdi_bus_device_pattern {
> +    cdi_device_type_t bus_type;
> +};
> +
> +/**
>   * \german
>   * Beschreibt ein Gerät
>   * \endgerman
> @@ -406,6 +417,19 @@ int cdi_provide_device(struct cdi_bus_data* device);
>  int cdi_provide_device_internal_drv(struct cdi_bus_data* device,
>                                      struct cdi_driver* driver);
>  
> +/**
> + * Tells the CDI implementation that the driver @drv is able to handle devices
> + * with the pattern @pattern (appearing on the bus @pattern->bus_type). This
> + * function can be called multiple times. Any device appearing on the bus not
> + * fitting the pattern will not be passed to the @drv->init_device() function.
> + * That function may however return NULL even after the driver has used this
> + * function, that is, it is valid to call this function with a @pattern that
> + * does not only fit devices handled by @drv but others as well (which can then
> + * be rejected by letting @drv->init_device() return NULL).
> + */
> +void cdi_handle_bus_device(struct cdi_driver* drv,
> +                           struct cdi_bus_device_pattern* pattern);

Is this supposed to be called in drv->init_driver()? If so, could be
worth mentioning.

Ideally it would just be part of the static driver declaration instead
of a separate function, but I imagine this is hard to achieve with both
the driver and device pattern being subclassed.

Kevin