[alsa-devel] ASoC driver parts probing order (MPC5200/MPC5121)

Mark Brown broonie at opensource.wolfsonmicro.com
Thu Oct 20 14:35:13 CEST 2011

On Thu, Oct 20, 2011 at 12:23:17PM +0200, David Jander wrote:

> of the probe function. So obviously, it is supposed that the DMA driver
> somehow gets probed before the PSC driver, but I can't see where this is
> enforced. AFAIK, the order is fairly random, so it could be the other way
> around.... and indeed, in my case it is.

The order the device model devices get probed in is entirely random and
any driver which is relying on this is buggy.

> 2.- Simply turning the dev_get/set_drvdata and chip initialization order
> around does work in my case, but doesn't seem a robust solution to me. Any
> idea how this should be handled?

I'd expect that delaying whatever relies on both devices being there
until the ASoC level probes happen is the way forward - you're
guaranteed that both deivces will be present there and the probe
ordering is guaranteed stable.

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