Re: [PATCH] drivercore: Add driver probe deferral mechanism

From: Greg KH
Date: Mon Jul 04 2011 - 13:41:45 EST


On Mon, Jul 04, 2011 at 11:11:59AM -0600, Grant Likely wrote:
> Allow drivers to report at probe time that they cannot get all the resources
> required by the device, and should be retried at a later time.

When is "later"?

And why would a driver not be able to get all of the proper resources?

Why can't a bus, at a later time, just try to reprobe everything when it
determines that it is a "later" time now, without having to do this
added change to the core?

> This should completely solve the problem of getting devices
> initialized in the right order. Right now this is mostly handled by
> mucking about with initcall ordering which is a complete hack, and
> doesn't even remotely handle the case where device drivers are in
> modules. This approach completely sidesteps the issues by allowing
> driver registration to occur in any order, and any driver can request
> to be retried after a few more other drivers get probed.

Why would drivers in modules be an issue? If a driver depends on
another driver, making it a module dependancy would solve the problem,
right?

thanks,

greg k-h
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