Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750778Ab0KVFF4 (ORCPT ); Mon, 22 Nov 2010 00:05:56 -0500 Received: from sm-d311v.smileserver.ne.jp ([203.211.202.206]:14174 "EHLO sm-d311v.smileserver.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767Ab0KVFFy (ORCPT ); Mon, 22 Nov 2010 00:05:54 -0500 Message-ID: <003201cb8a02$f05b15e0$66f8800a@maildom.okisemi.com> From: "Tomoya MORINAGA" To: "Marc Kleine-Budde" Cc: , "Masayuki Ohtake" , "Samuel Ortiz" , , , , , , , "Wolfgang Grandegger" , , "David S. Miller" , "Christian Pellegrin" , References: <4CE2434B.5050701@dsn.okisemi.com> <4CE27796.2000206@pengutronix.de> <007401cb87b1$a773b3d0$66f8800a@maildom.okisemi.com> <4CE64167.2030405@pengutronix.de> Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control, Date: Mon, 22 Nov 2010 14:05:52 +0900 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1983 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1983 X-Hosting-Pf: 0 X-NAI-Spam-Score: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 945 Lines: 23 On Friday, November 19, 2010 6:20 PM, Marc Kleine-Budde wrote : >>>> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags); >>>> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no); >>> Still we have the busy waiting in the TX path. Maybe you can move the >>> waiting before accessing the if[1] and remove the busy waiting here. >> I can't understand your saying. >> For transmitting data, calling pch_can_rw_msg_obj is mandatory. >Yes, but the busy wait is not needed. It should be enough to do the >busy-waiting _before_ accessing the if[1]. Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ? --- Thanks, Tomoya MORINAGA OKI SEMICONDUCTOR CO., LTD. -- 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/