Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754540Ab3EXOqm (ORCPT ); Fri, 24 May 2013 10:46:42 -0400 Received: from mail-lb0-f172.google.com ([209.85.217.172]:41327 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337Ab3EXOql (ORCPT ); Fri, 24 May 2013 10:46:41 -0400 Message-ID: <519F7D56.8080900@cogentembedded.com> Date: Fri, 24 May 2013 18:46:46 +0400 From: Sergei Shtylyov User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Federico Manzan CC: gregkh@linuxfoundation.org, sarah.a.sharp@linux.intel.com, stern@rowland.harvard.edu, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usbfs: Increase arbitrary limit for USB 3 isopkt length References: <1369385249-15624-1-git-send-email-f.manzan@gmail.com> In-Reply-To: <1369385249-15624-1-git-send-email-f.manzan@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1537 Lines: 46 Hello. On 24-05-2013 12:47, Federico Manzan wrote: > Increase the current arbitrary limit for isocronous packet size to a > value large enough to account for USB 3.0 super bandwidth streams, > bMaxBurst (0~15 allowed, 1~16 packets) > bmAttributes (bit 1:0, mult 0~2, 1~3 packets) > so the size max for one USB 3 isocronous transfer is > 1024 byte * 16 * 3 = 49152 byte > Signed-off-by: Federico Manzan > --- > drivers/usb/core/devio.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c > index caefc80..7ac137e 100644 > --- a/drivers/usb/core/devio.c > +++ b/drivers/usb/core/devio.c > @@ -1287,9 +1287,11 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb, > goto error; > } > for (totlen = u = 0; u < uurb->number_of_packets; u++) { > - /* arbitrary limit, > - * sufficient for USB 2.0 high-bandwidth iso */ > - if (isopkt[u].length > 8192) { > + /* arbitrary limit need for USB 3.0 > + * bMaxBurst (0~15 allowed, 1~16 packets) > + * bmAttributes (bit 1:0, mult 0~2, 1~3 packets) > + * sizemax: 1024 * 16 * 3 = 49152*/ The preferred style of the multi-line comments is this: /* * bla * bla */ WBR, Sergei -- 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/