Re: [PATCH v6 04/22] of: add function to allow probing a device from a OF node

From: Geert Uytterhoeven
Date: Mon Oct 26 2015 - 04:17:21 EST

On Mon, Sep 21, 2015 at 4:02 PM, Tomeu Vizoso
<tomeu.vizoso@xxxxxxxxxxxxx> wrote:
> Walks the OF tree up and finds the closest ancestor that has a struct
> device associated with it, probing it if isn't bound to a driver yet.
> The above should ensure that the dependency represented by the passed OF
> node is available, because probing a device should cause its descendants
> to be probed as well (when they get registered).
> Subsystems can use this when looking up resources for drivers, to reduce
> the chances of deferred probes because of the probing order of devices.
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>

Don't know to which response I should post this comment, so I'm responding
to the original email.

Some subsystems already do this.
If you call e.g. syscon_regmap_lookup_by_phandle(), it will call
of_syscon_register() if the syscon device pointed to hasn't been registered yet.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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