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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable 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 D82ACC43219 for ; Mon, 29 Apr 2019 08:09:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2EB52087B for ; Mon, 29 Apr 2019 08:09:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727608AbfD2IJ0 (ORCPT ); Mon, 29 Apr 2019 04:09:26 -0400 Received: from mailgw02.mediatek.com ([1.203.163.81]:27987 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727471AbfD2IJ0 (ORCPT ); Mon, 29 Apr 2019 04:09:26 -0400 X-UUID: 1a18ea539a324a15a23e18423d763b8a-20190429 X-UUID: 1a18ea539a324a15a23e18423d763b8a-20190429 Received: from mtkcas36.mediatek.inc [(172.27.4.253)] by mailgw02.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 801430977; Mon, 29 Apr 2019 16:09:16 +0800 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by MTKMBS31DR.mediatek.inc (172.27.6.102) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 29 Apr 2019 16:09:14 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Mon, 29 Apr 2019 16:09:13 +0800 Message-ID: <1556525353.24897.30.camel@mhfsdcap03> Subject: Re: [PATCH 2/6] net: stmmac: fix csr_clk can't be zero issue From: biao huang To: Alexandre Torgue CC: Jose Abreu , , "Giuseppe Cavallaro" , Maxime Coquelin , Matthias Brugger , , , , , , , Date: Mon, 29 Apr 2019 16:09:13 +0800 In-Reply-To: <24f4b268-aa7f-e1f7-59fc-2bc163eb8277@st.com> References: <1556433009-25759-1-git-send-email-biao.huang@mediatek.com> <1556433009-25759-3-git-send-email-biao.huang@mediatek.com> <24f4b268-aa7f-e1f7-59fc-2bc163eb8277@st.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, On Mon, 2019-04-29 at 09:18 +0200, Alexandre Torgue wrote: > Hi > > On 4/28/19 8:30 AM, Biao Huang wrote: > > The specific clk_csr value can be zero, and > > stmmac_clk is necessary for MDC clock which can be set dynamically. > > So, change the condition from plat->clk_csr to plat->stmmac_clk to > > fix clk_csr can't be zero issue. > > > > Signed-off-by: Biao Huang > > --- > > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > index 818ad88..9e89b94 100644 > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > @@ -4376,7 +4376,7 @@ int stmmac_dvr_probe(struct device *device, > > * set the MDC clock dynamically according to the csr actual > > * clock input. > > */ > > - if (!priv->plat->clk_csr) > > + if (priv->plat->stmmac_clk) > > stmmac_clk_csr_set(priv); > > else > > priv->clk_csr = priv->plat->clk_csr; > > > > So, as soon as stmmac_clk will be declared, it is no longer possible to > fix a CSR through the device tree ? let's focus on the condition: 1. clk_csr may be zero, it should not be the condition. or the clk_csr = 0 will jump to the wrong block. 2. Since stmmac_clk_csr_set will get_clk_rate from stmmac_clk, the plat->stmmac_clk is a more proper condition. In some case, it's impossible to get the clk rate of stmmac_clk, so it's better to remain the clk_csr flow.