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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 CB921C4338F for ; Tue, 10 Aug 2021 23:57:13 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 79AC860F55 for ; Tue, 10 Aug 2021 23:57:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 79AC860F55 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Uai2B8CsHNW7SKoe4mL/1mVd//378lmP5j/SqSEqCPo=; b=2/BM2HRDJFvwHY gEv+MxVx9BtNstaOrFLjup0BnGirliyuthfDoxJl0BvvRdX+j1gXLZZbTq9hmfJlCQqmYHnufQ5C9 CD5fY/wuQ+i4OHs2CMI7p3mu++vh49t4ZI5fNQaQjQzmYgzUD1AN/wOHcgohB/zzZHtSir7fkRlF6 QYz/3tK34xPku11unwNyibe9DTpK9WNnV3o/Ag+STCsjdXrGfu+hbbO+Fo1VHNEc/jQXSnBX3swxR 5o4AuqDNPFyfR3vbgnoZsBn8zQor1YaaRwREmXJEnCkZumxdOmX0+75RcfOpo8/s8s1ozOO2oJwlp HOocV0q5Q56VaUBODObw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDbay-00540Q-3c; Tue, 10 Aug 2021 23:55:44 +0000 Received: from mga12.intel.com ([192.55.52.136]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDbat-0053zj-Rw for linux-arm-kernel@lists.infradead.org; Tue, 10 Aug 2021 23:55:41 +0000 X-IronPort-AV: E=McAfee;i="6200,9189,10072"; a="194608370" X-IronPort-AV: E=Sophos;i="5.84,311,1620716400"; d="scan'208";a="194608370" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2021 16:55:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,311,1620716400"; d="scan'208";a="421996902" Received: from linux.intel.com ([10.54.29.200]) by orsmga003.jf.intel.com with ESMTP; 10 Aug 2021 16:55:36 -0700 Received: from linux.intel.com (vwong3-iLBPG3.png.intel.com [10.88.229.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 42F28580922; Tue, 10 Aug 2021 16:55:32 -0700 (PDT) Date: Wed, 11 Aug 2021 07:55:29 +0800 From: Wong Vee Khee To: Andrew Lunn Cc: Vivien Didelot , Florian Fainelli , "David S . Miller" , Jakub Kicinski , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Heiner Kallweit , Russell King , Voon Weifeng , Michael Sit Wei Hong , Vladimir Oltean , linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 1/2] net: pcs: xpcs: enable skip xPCS soft reset Message-ID: <20210810235529.GB30818@linux.intel.com> References: <20210809102229.933748-1-vee.khee.wong@linux.intel.com> <20210809102229.933748-2-vee.khee.wong@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210810_165539_940074_967EB6EB X-CRM114-Status: GOOD ( 22.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Andrew, On Mon, Aug 09, 2021 at 03:35:09PM +0200, Andrew Lunn wrote: > On Mon, Aug 09, 2021 at 06:22:28PM +0800, Wong Vee Khee wrote: > > From: Michael Sit Wei Hong > > > > Unlike any other platforms, Intel AlderLake-S uses Synopsys SerDes where > > all the SerDes PLL configurations are controlled by the xPCS at the BIOS > > level. If the driver perform a xPCS soft reset on initialization, these > > settings will be switched back to the power on reset values. > > > > This changes the xpcs_create function to take in an additional argument > > to check if the platform request to skip xPCS soft reset during device > > initialization. > > Why not just call into the BIOS and ask it to configure the SERDES? > Isn't that what ACPI is all about, hiding the details from the OS? Or > did the BIOS writers not add a control method to do this? > > Andrew BIOS does configured the SerDes. The problem here is that all the configurations done by BIOS are being reset at xpcs_create(). We would want user of the pcs-xpcs module (stmmac, sja1105) to have control whether or not we need to perform to the soft reset in the xpcs_create() call. Hope that explained. Regards, VK _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel