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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA4D0C433FE for ; Wed, 10 Nov 2021 04:10:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6355461186 for ; Wed, 10 Nov 2021 04:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230333AbhKJENF (ORCPT ); Tue, 9 Nov 2021 23:13:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:53584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230221AbhKJENC (ORCPT ); Tue, 9 Nov 2021 23:13:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id EA2CA61184; Wed, 10 Nov 2021 04:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636517416; bh=G+6fVK7jAdXV3OQ+8vLKg8mn15HTfheweA4+GGlagMU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KjMaZsw+Q1ZkaLcoDz6CsorLkHSYpgJfJQvw7YpIt5+TpgvZuxkrX4ctXSG3YyuCO K45Flo34BNnM7fbt2kmwpi7fCvxuwWRPPUuCQVDg97vzRzXXTfMChjmbt8DzskTLCm hHktSvQFsQfYMo1W2mQ7GMl2hZHlG43tykIYG/+qXHP+lomoMs8aVfj3xLIgt/wQai Sso/dEKGUECE+T/SyhZSFy4npCOnrxQL/vDUVTMfU+k2zRi6WUsF/y1gcQbCn9swIx F0rdgiHx1i0vHbEy7e6jBPrWv71zAtMjISkasvaCaHECcLizFDv56sICrv2i+Yg22+ cFdA2BSYP42tA== From: =?UTF-8?q?Marek=20Beh=C3=BAn?= To: netdev@vger.kernel.org, Andrew Lunn Cc: Jakub Kicinski , David Miller , Russell King , =?UTF-8?q?Marek=20Beh=C3=BAn?= Subject: [PATCH net 2/3] net: dsa: mv88e6xxx: Fix reading sgmii link status register Date: Wed, 10 Nov 2021 05:10:09 +0100 Message-Id: <20211110041010.2402-2-kabel@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211110041010.2402-1-kabel@kernel.org> References: <20211110041010.2402-1-kabel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The documentation says this about the SerDes PHY register 4.2001.2: This register bit indicates when link was lost since the last read. For the current link status, read this register back-to-back. Thus we need to read it twice to get the current value of the register. The wrong value is read when phylink requests change from sgmii to 2500base-x mode, and link won't come up. This fixes the bug. Fixes: a5a6858b793f ("net: dsa: mv88e6xxx: extend phylink to Serdes PHYs") Signed-off-by: Marek Behún --- drivers/net/dsa/mv88e6xxx/serdes.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c index 6ea003678798..bc198ef06745 100644 --- a/drivers/net/dsa/mv88e6xxx/serdes.c +++ b/drivers/net/dsa/mv88e6xxx/serdes.c @@ -1041,15 +1041,25 @@ static void mv88e6390_serdes_irq_link_sgmii(struct mv88e6xxx_chip *chip, u16 bmsr; int err; - /* If the link has dropped, we want to know about it. */ + /* If the link has dropped, we want to know about it. + * This register bit indicates when link was lost since the last read. + * We need to read it twice to get the current value. + */ err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS, MV88E6390_SGMII_BMSR, &bmsr); - if (err) { - dev_err(chip->dev, "can't read Serdes BMSR: %d\n", err); - return; - } + if (err) + goto err; + + err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS, + MV88E6390_SGMII_BMSR, &bmsr); + if (err) + goto err; dsa_port_phylink_mac_change(chip->ds, port, !!(bmsr & BMSR_LSTATUS)); + + return; +err: + dev_err(chip->dev, "can't read Serdes BMSR: %d\n", err); } static void mv88e6393x_serdes_irq_link_10g(struct mv88e6xxx_chip *chip, -- 2.32.0