Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758270AbWK0PDH (ORCPT ); Mon, 27 Nov 2006 10:03:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758271AbWK0PDG (ORCPT ); Mon, 27 Nov 2006 10:03:06 -0500 Received: from firewall.rowland.harvard.edu ([140.247.233.35]:42132 "HELO netrider.rowland.org") by vger.kernel.org with SMTP id S1758270AbWK0PDE (ORCPT ); Mon, 27 Nov 2006 10:03:04 -0500 Date: Mon, 27 Nov 2006 10:03:02 -0500 (EST) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: Duncan Sands cc: Ilyes Gouta , , Subject: Re: [linux-usb-devel] [USB] urb->number_of_packets = 256 ! In-Reply-To: <200611270932.30564.duncan.sands@math.u-psud.fr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 985 Lines: 24 On Mon, 27 Nov 2006, Duncan Sands wrote: > Hi Ilyes, you won't be able to allocate that much *contiguous* memory, > but you should be able to allocate enough non-contiguous memory (e.g. > by calling __get_free_page 256 times; not the same as calling > __get_free_pages(8) !). To use that memory, you can try using the usb > scatter/gather support (see usb.h); I don't know if it works with > isochronous urbs though. I've CC'd the usb development list - maybe > someone there can help. The scatter/gather library does not support iso. > > Splitting the transfer across multiple URB doesn't seem to work (I didn't really > > investigate in depth this possibility). It should work. Go back and try it again more carefully. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/