From patchwork Wed Nov 24 06:10:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Hung X-Patchwork-Id: 12636135 X-Patchwork-Delegate: kuba@kernel.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC37CC433EF for ; Wed, 24 Nov 2021 06:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234770AbhKXGPQ (ORCPT ); Wed, 24 Nov 2021 01:15:16 -0500 Received: from twspam01.aspeedtech.com ([211.20.114.71]:34975 "EHLO twspam01.aspeedtech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234307AbhKXGPQ (ORCPT ); Wed, 24 Nov 2021 01:15:16 -0500 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 1AO5klpJ059581; Wed, 24 Nov 2021 13:46:47 +0800 (GMT-8) (envelope-from dylan_hung@aspeedtech.com) Received: from DylanHung-PC.aspeed.com (192.168.2.216) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 24 Nov 2021 14:10:54 +0800 From: Dylan Hung To: , , , , , , , , , , CC: Subject: [PATCH] net:phy: Fix "Link is Down" issue Date: Wed, 24 Nov 2021 14:10:57 +0800 Message-ID: <20211124061057.12555-1-dylan_hung@aspeedtech.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [192.168.2.216] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-DNSRBL: X-MAIL: twspam01.aspeedtech.com 1AO5klpJ059581 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The issue happened randomly in runtime. The message "Link is Down" is popped but soon it recovered to "Link is Up". The "Link is Down" results from the incorrect read data for reading the PHY register via MDIO bus. The correct sequence for reading the data shall be: 1. fire the command 2. wait for command done (this step was missing) 3. wait for data idle 4. read data from data register Fixes: a9770eac511a ("net: mdio: Move MDIO drivers into a new subdirectory") Signed-off-by: Dylan Hung Reviewed-by: Joel Stanley --- drivers/net/mdio/mdio-aspeed.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c index cad820568f75..966c3b4ad59d 100644 --- a/drivers/net/mdio/mdio-aspeed.c +++ b/drivers/net/mdio/mdio-aspeed.c @@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum) iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); + rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl, + !(ctrl & ASPEED_MDIO_CTRL_FIRE), + ASPEED_MDIO_INTERVAL_US, + ASPEED_MDIO_TIMEOUT_US); + if (rc < 0) + return rc; + rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data, data & ASPEED_MDIO_DATA_IDLE, ASPEED_MDIO_INTERVAL_US,