From patchwork Fri Jul 2 10:17:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12355875 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=-16.8 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 74766C11F68 for ; Fri, 2 Jul 2021 10:18:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55C376141C for ; Fri, 2 Jul 2021 10:18:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231382AbhGBKUr (ORCPT ); Fri, 2 Jul 2021 06:20:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231593AbhGBKUp (ORCPT ); Fri, 2 Jul 2021 06:20:45 -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 55BE6C061765 for ; Fri, 2 Jul 2021 03:18:13 -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 1lzGFH-0005BA-3s; Fri, 02 Jul 2021 12:18:03 +0200 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lzGFF-0003ea-Gb; Fri, 02 Jul 2021 12:18:01 +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 v2 1/6] net: dsa: qca: ar9331: reorder MDIO write sequence Date: Fri, 2 Jul 2021 12:17:46 +0200 Message-Id: <20210702101751.13168-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210702101751.13168-1-o.rempel@pengutronix.de> References: <20210702101751.13168-1-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 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 | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/net/dsa/qca/ar9331.c b/drivers/net/dsa/qca/ar9331.c index ca2ad77b71f1..6686192e1883 100644 --- a/drivers/net/dsa/qca/ar9331.c +++ b/drivers/net/dsa/qca/ar9331.c @@ -837,16 +837,24 @@ 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); + /* 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, the result and + * configuration of request in the second half. + * To make it work properly, we should do the second part of transfer + * before the first one is done. + */ + 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;