From patchwork Sat Apr 3 11:48:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12181901 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 D6123C43462 for ; Sat, 3 Apr 2021 11:49:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E8046127B for ; Sat, 3 Apr 2021 11:49:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236762AbhDCLtO (ORCPT ); Sat, 3 Apr 2021 07:49:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236736AbhDCLtN (ORCPT ); Sat, 3 Apr 2021 07:49:13 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB8C9C061793 for ; Sat, 3 Apr 2021 04:49:09 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lSelp-0000es-7B; Sat, 03 Apr 2021 13:48:53 +0200 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lSell-0007xp-OX; Sat, 03 Apr 2021 13:48:49 +0200 From: Oleksij Rempel To: Andrew Lunn , Vivien Didelot , Florian Fainelli , Vladimir Oltean , "David S. Miller" , Jakub Kicinski , Russell King Cc: Oleksij Rempel , Pengutronix Kernel Team , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org Subject: [PATCH net-next v1 3/9] net: dsa: qca: ar9331: reorder MDIO write sequence Date: Sat, 3 Apr 2021 13:48:42 +0200 Message-Id: <20210403114848.30528-4-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210403114848.30528-1-o.rempel@pengutronix.de> References: <20210403114848.30528-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-mips@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In case of this switch we work with 32bit registers on top of 16bit bus. Some registers (for example access to forwarding database) have trigger bit on the first 16bit half of request and the result + configuration of request in the second half. Without this this patch, we would trigger database operation and overwrite result in one run. To make it work properly, we should do the second part of transfer before the first one is done. So far, this rule seems to work for all registers on this switch. Signed-off-by: Oleksij Rempel Reviewed-by: Andrew Lunn --- drivers/net/dsa/qca/ar9331.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/dsa/qca/ar9331.c b/drivers/net/dsa/qca/ar9331.c index ca2ad77b71f1..9a5035b2f0ff 100644 --- a/drivers/net/dsa/qca/ar9331.c +++ b/drivers/net/dsa/qca/ar9331.c @@ -837,16 +837,17 @@ static int ar9331_mdio_write(void *ctx, u32 reg, u32 val) return 0; } - ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg, val); + ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg + 2, + val >> 16); if (ret < 0) goto error; - ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg + 2, - val >> 16); + ret = __ar9331_mdio_write(sbus, AR9331_SW_MDIO_PHY_MODE_REG, reg, val); if (ret < 0) goto error; return 0; + error: dev_err_ratelimited(&sbus->dev, "Bus error. Failed to write register.\n"); return ret;