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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 2C958C433E1 for ; Sat, 4 Jul 2020 12:45:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AFDE208B8 for ; Sat, 4 Jul 2020 12:45:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TDFVSWxt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727929AbgGDMpc (ORCPT ); Sat, 4 Jul 2020 08:45:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726738AbgGDMp3 (ORCPT ); Sat, 4 Jul 2020 08:45:29 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27DCDC061794 for ; Sat, 4 Jul 2020 05:45:29 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id w6so37250906ejq.6 for ; Sat, 04 Jul 2020 05:45:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=O+O8SWajzOmww2WQh1LfPXn4BW3djglpBsXVmmWeTPo=; b=TDFVSWxtbV/JZhOF3icIFzTzCO72goFZkuLwbXOYuZOtemrV3PbQkJ/N+EU9D1NuCo rQ2mjrQ3G9WI+Eq+8SOSmWsCkfnMn1Vw5cDziKg1i7vX93VdZTwFOPiKY3+QSORNnLZt liMLBhnvsMP/wpQymwiWO/KNAG6y4LVdVZghz3HrMRvkEZYk7vtjCnpb6hK2L6T8N/tx ERGlOs6dKENsltY+bB9rABK8ZoGWKanRMU7Pgim1XxwmPNfw7L8anDM970Gv2fg9/Llj GjNOEyHHTXTIEPZN2iHpRU9fVYitWW+I9Z+A6grFhZSYECBn9R7AGrFx+BZFeD3nBSVc 7j9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=O+O8SWajzOmww2WQh1LfPXn4BW3djglpBsXVmmWeTPo=; b=fdtSB7S/DLV8dPTbdayilaTPA9P+Nk47ZCee4oO764AFnWLiTa9OhqVJQmefYT51Rn O1rpz+2IZXrBf3RTIDQ3PujRjjw/4iXXmDv2QUVva1ii1p6m1uiXeN8pJ4NTsfNF2+/S sHJxwLbjUe16D+mWLQ2I5Gguab9EBAzcPJFBrueIt3seIkRYRgn4i+bCCxExctHjWHg2 e0gJJl8P86mEbvc+Ql1k22gl0P675F1ObrhRzFDES4oXBW9n/6a3AqNXVI5HYaaTZkCY ltzHRpr3vSohROmmTruc9rzsLD1p4lx39FKShYP4/2U8zl4SVt00W1k9SONxwpL/aWh2 1fCg== X-Gm-Message-State: AOAM533bdaNaYesCMcqLfzKC9hFQJuVGy1MycDvpmVZPdXzR8XjUEYZ/ xYmUZobyKKPJUdG/gQmeVNc= X-Google-Smtp-Source: ABdhPJz2eSnAiPtv9VEv6/fjXTQ5ONmPpVu+l0qtbpyOA0twO+n4gMcoS4TTdcdw1MH9vMkb2+2/KQ== X-Received: by 2002:a17:906:e215:: with SMTP id gf21mr30298660ejb.310.1593866727877; Sat, 04 Jul 2020 05:45:27 -0700 (PDT) Received: from localhost.localdomain ([188.25.219.134]) by smtp.gmail.com with ESMTPSA id dm1sm12983851ejc.99.2020.07.04.05.45.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 04 Jul 2020 05:45:27 -0700 (PDT) From: Vladimir Oltean To: davem@davemloft.net, netdev@vger.kernel.org Cc: andrew@lunn.ch, f.fainelli@gmail.com, vivien.didelot@gmail.com, claudiu.manoil@nxp.com, alexandru.marginean@nxp.com, ioana.ciornei@nxp.com, linux@armlinux.org.uk Subject: [PATCH v2 net-next 1/6] net: dsa: felix: clarify the intention of writes to MII_BMCR Date: Sat, 4 Jul 2020 15:45:02 +0300 Message-Id: <20200704124507.3336497-2-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200704124507.3336497-1-olteanv@gmail.com> References: <20200704124507.3336497-1-olteanv@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vladimir Oltean The driver appears to write to BMCR_SPEED and BMCR_DUPLEX, fields which are read-only, since they are actually configured through the vendor-specific IF_MODE (0x14) register. But the reason we're writing back the read-only values of MII_BMCR is to alter these writable fields: BMCR_RESET BMCR_LOOPBACK BMCR_ANENABLE BMCR_PDOWN BMCR_ISOLATE BMCR_ANRESTART In particular, the only field which is really relevant to this driver is BMCR_ANENABLE. Clarify that intention by spelling it out, using phy_set_bits and phy_clear_bits. The driver also made a few writes to BMCR_RESET and BMCR_ANRESTART which are unnecessary and may temporarily disrupt the link to the PHY. Remove them. Signed-off-by: Vladimir Oltean --- Changes in v2: Patch is new. drivers/net/dsa/ocelot/felix_vsc9959.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 2067776773f7..9f4c8343652f 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -815,7 +815,7 @@ static void vsc9959_pcs_init_sgmii(struct phy_device *pcs, phy_write(pcs, ENETC_PCS_LINK_TIMER2, ENETC_PCS_LINK_TIMER2_VAL); - phy_write(pcs, MII_BMCR, BMCR_ANRESTART | BMCR_ANENABLE); + phy_set_bits(pcs, MII_BMCR, BMCR_ANENABLE); } else { int speed; @@ -845,10 +845,7 @@ static void vsc9959_pcs_init_sgmii(struct phy_device *pcs, ENETC_PCS_IF_MODE_SGMII_EN | ENETC_PCS_IF_MODE_SGMII_SPEED(speed)); - /* Yes, not a mistake: speed is given by IF_MODE. */ - phy_write(pcs, MII_BMCR, BMCR_RESET | - BMCR_SPEED1000 | - BMCR_FULLDPLX); + phy_clear_bits(pcs, MII_BMCR, BMCR_ANENABLE); } } @@ -882,9 +879,7 @@ static void vsc9959_pcs_init_2500basex(struct phy_device *pcs, ENETC_PCS_IF_MODE_SGMII_EN | ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_2500)); - phy_write(pcs, MII_BMCR, BMCR_SPEED1000 | - BMCR_FULLDPLX | - BMCR_RESET); + phy_clear_bits(pcs, MII_BMCR, BMCR_ANENABLE); } static void vsc9959_pcs_init_usxgmii(struct phy_device *pcs, -- 2.25.1