Re: [stable] Re: [PATCH] Re: bug in handling of highspeed usb HID devices

[Greg KH <greg@kroah.com>]

On Fri, Oct 14, 2005 at 07:46:02PM +0200, Christian Krause wrote:
> On Fri, 14 Oct 2005 10:13:26 -0700, Greg KH wrote:
> 
> > On Thu, Oct 13, 2005 at 02:25:18PM -0700, Chris Wright wrote:
> >> * kernel-stuff@comcast.net (kernel-stuff@comcast.net) wrote:
> >> > This seems to be -stable material since it's a clear cut bug with bad
> >> > consequences. 
> >> > 
> >> > Chris Wright - is the below patch acceptable for -stable?
> 
> > Also, I don't think this should go into -stable, as there are no
> > high-speed HID devices available right now, so it really isn't affecting
> > anyone :)
> 
> No, that's no correct. There are such devices:
> 
> Newer KVM-over-IP appliances, like the Avocent's DSR2030 emulates
> keyboard, mouse and a mass storage device over USB. I've tested this
> specific device with linux and the USB transfers are Highspeed and the
> USB device has one interface which is HID. So there are Highspeed USB
> devices out there. 

Ah, ok, thanks, I wasn't aware of these devices.

> With all respect, but I don't really understand why this is important.
> The linux kernel clearly violates the USB specification. The calculation of
> the real polling interval for interrupt endpoints is
> i = 2^(bInterval-1) (according to USB 2.0 spec, chapter 9.6.6) and _not_
> i = 2^((2^(bInterval-1))-1) as it is calculated in linux.
> This is clearly a bug in linux and should be fixed.

No one is arguing that it shouldn't be.

thanks,

greg k-h