Re: Kernel 2.6.22 some Logitech webcams

On Thu, 4 Oct 2007, Laurent Pinchart wrote:

> There are two ways to work around the problem. Either slow the USB stack down 
> to bring it to Windows' level, or get the uvcvideo driver to bind to the 
> video interface after the usbaudio driver has bound to the audio interface.
> 
> The first solution is obviously not possible (and far from desired anyway), so 
> I'm looking for a way to implement the second solution.
> 
> The bad devices I work with have video interfaces and audio interfaces, in 
> that order. The USB stack thus tries to bind the video driver before the 
> audio driver.
> 
> Starting at kernel 2.6.22, the patch I mentioned in my previous mail triggers 
> a bug in the device. I noticed that binding the usbaudio driver before the 
> uvcvideo driver works around the device bug. I'm thus looking for a way to do 
> this automatically, as the USB stack will bind drivers in the USB interfaces 
> order.

One possibility is to have the uvcvideo probe routine check whether the 
audio interface is bound.  If it isn't, have the probe fail and start 
up a delayed workqueue routine to probe again 5 seconds later.  It's a 
nasty hack, but it ought to work.

Alan Stern


-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel