Re: u3g and ubsa

On Wed, 2008-11-26 at 10:29 +0100, Nick Hibma wrote:
> Could you try the following:
> 
> Change the ibufsize and obufsize values to a power of 2 in u3g_attach:
> 
>              ucom->sc_ibufsize = 4096;
>              ucom->sc_ibufsizepad = ucom->sc_ibufsize;
>              ucom->sc_obufsize = 4096;
> 
> Perhaps the USB stack does not like arbitrarily sized buffers due to 
> transfer rollovers at the end of the buffer / memory page or something.
> 
> If that does not work could you lower it to 512, and if that does not work 
> change it to:
> 
>              ucom->sc_ibufsize = UGETW(ed->wMaxPacketSize);
>              ucom->sc_ibufsizepad = ucom->sc_ibufsize;
>              ucom->sc_obufsize = UGETW(ed->wMaxPacketSize);
> 
> That last case is worst case as it would considerably increase overhead, 
> especially in USB 1.0 cases where the max. wMaxPacketSize is 64 bytes.

All cases makes same panic on connecting to port: 
ohci.c:545     ohci_alloc_std_chain: XXX need to copy


> If it works I'd be interested to hear about performance (download from SUN 
> is always a good one), and any messages in dmesg or in a ppp logfile for 
> dropped chars, and invalid FCS.
> 
> Cheers,
> 
> Nick
-- 
Vladimir B. Grebenschikov
vova_at_fbsd.ru