iso support

[Stanislaw Gruszka]

> On iso urb error status isn't keep in urb->status variable,
> it's in iso_frame_dest[i].status for every frame and (AFAIK) urb->status 
> is equal to -EILSEQ allways. So to proper driver work in iso mode
> Matthieu condition change in usbatm_complete() is needed.

Hi all, hi Duncan, as you will work tomorrow on driver please take 
into account iso support too.

I tried to take more deeply look at urb->status in iso mode. 
Of course I was wrong telling urb->status is equal -EILSEQ  
allways, it's only quite frequency situation on uhci host controller
(which I have on my machine). After my investigation on uhci driver code, 
seems urb->status is equal last non zero iso_frame_desc[i].status or zero. 
Eg: if all frames are ok there usb->status is 0. In iso mode if reserved bandwitch 
is greater then real bandwitch, there are incoming frames without any data 
and such with EILSEQ error. This is the reason why on uhci there 
are lot of urb->status == -EILSEQ.

Otherwise situation is on ohci HCD where urb->status is allways 0 
on isoc urb.

Generally it's not clear urb->status should be ignored on isoc urb
or not, in my opinion it should be ignored and something like this
is needed on usbatm_complete():

	if (usb_pipebulk(urb->pipe) && unlikely(urb->status))
		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
	else
		tasklet_schedule(&channel->tasklet);

__
Regards
Staszek Gruszka