Re: [PATCH RFC] USB: Add HCD fastboot

Alan Stern
2008-08-06T19:11:26Z

On Wed, 6 Aug 2008, Simon Arlott wrote:

> On 31/07/08 20:16, Alan Stern wrote:
> >> > It's not entirely clear why usblp is blocking at all. Probably because
> >> > it is waiting on the device semaphores for devices that are currently
> >> > being probed -- the driver core won't allow two threads to probe the
> >> > same device concurrently.
> >>
> >> Ok - so there could be some big improvements to be had by making the hcd
> >> init happen as early as possible and the device initcalls later?
> >
> > Maybe. Perhaps a better approach would be to make the device driver
> > initcalls before there are any devices for their probe routines to
> > block on.
>
> What about this?
>
> The Makefiles become a bit messy, but by moving things around I get the
> desired effect without splitting their initcalls.

Wouldn't it be much simpler, and less objectionable, to do what I
suggested earlier? That is, add a 5-second delay at the start of
hub_thread() in drivers/usb/core/hub.c. No messing with Makefiles, no
changes to the initcall scheduling.

Alan Stern