From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760364AbZEFPdu (ORCPT ); Wed, 6 May 2009 11:33:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757214AbZEFPdF (ORCPT ); Wed, 6 May 2009 11:33:05 -0400 Received: from kroah.org ([198.145.64.141]:37485 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755650AbZEFPdB (ORCPT ); Wed, 6 May 2009 11:33:01 -0400 Date: Wed, 6 May 2009 08:26:53 -0700 From: Greg KH To: Jason Wessel Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/5] usb_debug: implement multi urb write Message-ID: <20090506152653.GC4603@kroah.com> References: <1241575205-12199-1-git-send-email-jason.wessel@windriver.com> <1241575205-12199-2-git-send-email-jason.wessel@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1241575205-12199-2-git-send-email-jason.wessel@windriver.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 05, 2009 at 09:00:01PM -0500, Jason Wessel wrote: > The usb_debug driver, when used as the console, will always fail to > insert the carriage return and new line sequence as well as randomly > drop console output. This is a result of only having the single > write_urb and that the tty layer will have a lock that prevents the > processing of the back to back urb requests. > > The solution is to allow more than one urb to be outstanding and have > a slightly deeper transmit queue. The idea and some code is borrowed > from the ftdi_sio usb driver. Almost all usb-serial drivers need this functionality. As you are adding it to the usb_debug driver, why not just add this kind of functionality to the usb-serial core instead, that way we can share it with all of the drivers? I'd much rather see that happen instead of us doing it individually again. thanks, greg k-h