Re: klists and struct device semaphores

From: Patrick Mochel
Date: Wed Mar 30 2005 - 21:18:07 EST



On Tue, 29 Mar 2005, Alan Stern wrote:

> On Mon, 28 Mar 2005, Patrick Mochel wrote:
>
> > How is this related to (8) above? Do you need some sort of protected,
> > short path through the core to add the device, but not bind it or add it
> > to the PM core?
>
> Having thought it through, I believe all we need for USB support is this:
>
> Whenever usb_register() in the USB core calls driver_register()
> and the call filters down to driver_attach(), that routine
> should lock dev->parent->sem before calling driver_probe_device()
> (and unlock it afterward, of course).
>
> (For the corresponding remove pathway, where usb_deregister()
> calls driver_unregister(), it would be nice if __remove_driver()
> locked dev->parent->sem before calling device_release_driver().
> This is not really needed, however, since USB drivers aren't
> supposed to touch the device in their disconnect() method.)


Why can't you just lock it in ->probe() and ->remove() yourself?


Pat

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