From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Petter Selasky Subject: Re: [PATCH/RFC 5/5] usb: Add support for streams alloc/dealloc to devio.c Date: Mon, 22 Aug 2011 09:58:21 +0200 Message-ID: <201108220958.21618.hselasky@c2i.net> References: <20110818224713.GA6738@xanatos> <7e62861a4ff90aa7990dda5563340797.squirrel@www.codeaurora.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from mailfe05.c2i.net ([212.247.154.130]:58827 "EHLO swip.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752057Ab1HVIAv (ORCPT ); Mon, 22 Aug 2011 04:00:51 -0400 In-Reply-To: <7e62861a4ff90aa7990dda5563340797.squirrel@www.codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Amit Blay Cc: Sarah Sharp , Tatyana Brokhman , greg@kroah.com, linux-usb@vger.kernel.org, linux-arm-msm@vger.kernel.org, balbi@ti.com, Amit Blay , open list On Sunday 21 August 2011 12:18:34 Amit Blay wrote: > Thanks Sarah, Hans for your comments, > > On Thu, August 18, 2011 3:47 pm, Sarah Sharp wrote: > > Yes, I think this is the correct solution. Sorry for taking so long to > > get back to you. > > OK, so I will go ahead with implementing this solution. > > > On Wed, Aug 17, 2011 at 09:06:03AM +0200, Hans Petter Selasky wrote: > >> I would suggest overloading the "unsigned int pipe", instead of breaking > >> existing API's by adding a new stream ID value. Also for LibUSB. > > The purposed solution will not break any existing API, by doing the > following: > a. Adding a new API for streams alloc/dealloc > b. Adding a new API for submitting a URB which is stream capable (I will > implement this in a separate patch). > > > I don't see this as a strong argument why we should arbitrarily limit a > > new API. It's very hard to deprecate kernel to userspace API, so I > > think we should do it right the first time. There are current > > applications (like an SSD behind a UAS device) that need as many > > concurrent streams in flight as possible, so I don't buy the argument > > that there aren't current applications that need that many streams. > > I agree with Sarah. > Hans, I appreciate your inputs. Please let me know if you see a good > reason why not implementing the new APIs purposed above for streams > allocation and usage. Otherwise I will go ahead with the implementation. Hi Amit, I think your suggestion is OK. --HPS