From patchwork Thu Nov 25 02:44:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Hung X-Patchwork-Id: 12638395 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 AEFB4C433EF for ; Thu, 25 Nov 2021 02:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237267AbhKYCwD (ORCPT ); Wed, 24 Nov 2021 21:52:03 -0500 Received: from twspam01.aspeedtech.com ([211.20.114.71]:30296 "EHLO twspam01.aspeedtech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229963AbhKYCuC (ORCPT ); Wed, 24 Nov 2021 21:50:02 -0500 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 1AP2JVcS073363; Thu, 25 Nov 2021 10:19:31 +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; Thu, 25 Nov 2021 10:43:41 +0800 From: Dylan Hung To: , , , , , , , , , , CC: , Subject: [PATCH v2] mdio: aspeed: Fix "Link is Down" issue Date: Thu, 25 Nov 2021 10:44:32 +0800 Message-ID: <20211125024432.15809-1-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 1AP2JVcS073363 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: f160e99462c6 ("net: phy: Add mdio-aspeed") Cc: stable@vger.kernel.org Reviewed-by: Joel Stanley Signed-off-by: Dylan Hung Reviewed-by: Andrew Lunn Reviewed-by: Russell King (Oracle) --- v2: revise commit message 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,