From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 362A5C4727C for ; Wed, 30 Sep 2020 14:50:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E568820659 for ; Wed, 30 Sep 2020 14:50:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730230AbgI3Oul (ORCPT ); Wed, 30 Sep 2020 10:50:41 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:37093 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729767AbgI3Oul (ORCPT ); Wed, 30 Sep 2020 10:50:41 -0400 X-Greylist: delayed 3535 seconds by postgrey-1.27 at vger.kernel.org; Wed, 30 Sep 2020 10:50:40 EDT X-Originating-IP: 86.206.245.199 Received: from windsurf.home (lfbn-tou-1-420-199.w86-206.abo.wanadoo.fr [86.206.245.199]) (Authenticated sender: thomas.petazzoni@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 0A1071BF20B; Wed, 30 Sep 2020 14:50:37 +0000 (UTC) Date: Wed, 30 Sep 2020 16:50:37 +0200 From: Thomas Petazzoni To: Andy Shevchenko Cc: Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , Linux Kernel Mailing List , Jan =?UTF-8?B?S3VuZHLDoXQ=?= , Mark Brown , linux-spi Subject: Re: [PATCH] serial: max310x: rework RX interrupt handling Message-ID: <20200930165037.77813365@windsurf.home> In-Reply-To: References: <20200930135137.197592-1-thomas.petazzoni@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.6 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hello, On Wed, 30 Sep 2020 17:24:48 +0300 Andy Shevchenko wrote: > > On a Microchip SAMA5D3 platform that is receiving 20 bytes every 16ms > > over one MAX310X UART, this patch has allowed to reduce the CPU > > consumption of the interrupt handler thread from ~25% to 6-7%. > > Was it always like this? As far as I can see, yes. I guess you were thinking about a Fixes: tag perhaps? I don't think a Fixes: tag really applies here, as we're not fixing a performance regression. > Reviewed-by: Andy Shevchenko > > - /* Configure MODE2 register & Reset FIFOs*/ > > - val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT; > > - max310x_port_write(port, MAX310X_MODE2_REG, val); > > + /* Reset FIFOs*/ > > Add a space before the asterisk. Indeed. Let me know if a v2 is needed, or if this small typo can be fixed when applying. Thanks, Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com