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Date: Fri, 10 Jun 2011 11:21:59 -0400 (EDT)
From: Alan Stern <stern@rowland.harvard.edu>
To: Mauro Carvalho Chehab <mchehab@infradead.org>
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Subject: Re: Improving kernel -> userspace (usbfs)  usb device hand off
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On Fri, 10 Jun 2011, Mauro Carvalho Chehab wrote:

> Em 10-06-2011 11:48, Alan Stern escreveu:
> > On Fri, 10 Jun 2011, Hans de Goede wrote:
> > 
> > 
> > As Felipe has mentioned, this sounds like the sort of problem that 
> > can better be solved in userspace.  A dual-mode device like the one 
> > you describe really is either a still-cam or a webcam, never both at 
> > the same time.  Hence what users need is a utility program to switch 
> > modes (by loading/unloading the appropriate programs or drivers). 
> 
> Unloading a driver in order to access the hardware via userspace?
> This sounds a very bad idea do me. What happens if another hardware 
> is using the same driver?

A kernel driver wouldn't have to be unloaded.  It could simply be 
unbound from the device via sysfs or usbfs.

Alan STern