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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 75F1BC433E0 for ; Tue, 26 May 2020 21:04:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45675206D5 for ; Tue, 26 May 2020 21:04:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728694AbgEZVEa (ORCPT ); Tue, 26 May 2020 17:04:30 -0400 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:34869 "EHLO relay9-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726858AbgEZVEa (ORCPT ); Tue, 26 May 2020 17:04:30 -0400 X-Originating-IP: 86.202.110.81 Received: from localhost (lfbn-lyo-1-15-81.w86-202.abo.wanadoo.fr [86.202.110.81]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 144C3FF805; Tue, 26 May 2020 21:04:26 +0000 (UTC) Date: Tue, 26 May 2020 23:04:26 +0200 From: Alexandre Belloni To: Antoine Tenart Cc: davem@davemloft.net, andrew@lunn.ch, f.fainelli@gmail.com, hkallweit1@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, allan.nielsen@microchip.com Subject: Re: [PATCH net-next 1/4] net: phy: mscc-miim: use more reasonable delays Message-ID: <20200526210426.GG3972@piout.net> References: <20200526162256.466885-1-antoine.tenart@bootlin.com> <20200526162256.466885-2-antoine.tenart@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200526162256.466885-2-antoine.tenart@bootlin.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/05/2020 18:22:53+0200, Antoine Ténart wrote: > The MSCC MIIM MDIO driver uses delays to read poll a status register. I > made multiple tests on a Ocelot PCS120 platform which led me to reduce > those delays. The delay in between which the polling function is allowed > to sleep is reduced from 100us to 50us which in almost all cases is a > good value to succeed at the first retry. The overall delay is also > lowered as the prior value was really way to high, 10000us is large > enough. > > Signed-off-by: Antoine Tenart Reviewed-by: Alexandre Belloni > --- > drivers/net/phy/mdio-mscc-miim.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/phy/mdio-mscc-miim.c b/drivers/net/phy/mdio-mscc-miim.c > index badbc99bedd3..0b7544f593fb 100644 > --- a/drivers/net/phy/mdio-mscc-miim.c > +++ b/drivers/net/phy/mdio-mscc-miim.c > @@ -44,7 +44,7 @@ static int mscc_miim_wait_ready(struct mii_bus *bus) > u32 val; > > readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val, > - !(val & MSCC_MIIM_STATUS_STAT_BUSY), 100, 250000); > + !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50, 10000); > if (val & MSCC_MIIM_STATUS_STAT_BUSY) > return -ETIMEDOUT; > > -- > 2.26.2 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com