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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 2F133C65BAF for ; Sun, 9 Dec 2018 22:23:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9DE220661 for ; Sun, 9 Dec 2018 22:23:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9DE220661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728164AbeLIWX0 (ORCPT ); Sun, 9 Dec 2018 17:23:26 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35114 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726490AbeLIVzT (ORCPT ); Sun, 9 Dec 2018 16:55:19 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW72h-0002iZ-Qn; Sun, 09 Dec 2018 21:55:16 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72e-0003RB-CV; Sun, 09 Dec 2018 21:55:12 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Claudiu Beznea" , "Anssi Hannula" , "David S. Miller" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 161/328] net: macb: do not disable MDIO bus at open/close time In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Anssi Hannula commit 0da70f808029476001109b6cb076737bc04cea2e upstream. macb_reset_hw() is called from macb_close() and indirectly from macb_open(). macb_reset_hw() zeroes the NCR register, including the MPE (Management Port Enable) bit. This will prevent accessing any other PHYs for other Ethernet MACs on the MDIO bus, which remains registered at macb_reset_hw() time, until macb_init_hw() is called from macb_open() which sets the MPE bit again. I.e. currently the MDIO bus has a short disruption at open time and is disabled at close time until the interface is opened again. Fix that by only touching the RE and TE bits when enabling and disabling RX/TX. v2: Make macb_init_hw() NCR write a single statement. Fixes: 6c36a7074436 ("macb: Use generic PHY layer") Signed-off-by: Anssi Hannula Reviewed-by: Claudiu Beznea Tested-by: Claudiu Beznea Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings --- --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -1257,14 +1257,18 @@ static void macb_init_rings(struct macb static void macb_reset_hw(struct macb *bp) { + u32 ctrl = macb_readl(bp, NCR); + /* * Disable RX and TX (XXX: Should we halt the transmission * more gracefully?) */ - macb_writel(bp, NCR, 0); + ctrl &= ~(MACB_BIT(RE) | MACB_BIT(TE)); /* Clear the stats registers (XXX: Update stats first?) */ - macb_writel(bp, NCR, MACB_BIT(CLRSTAT)); + ctrl |= MACB_BIT(CLRSTAT); + + macb_writel(bp, NCR, ctrl); /* Clear all status flags */ macb_writel(bp, TSR, -1); @@ -1400,7 +1404,7 @@ static void macb_init_hw(struct macb *bp macb_writel(bp, TBQP, bp->tx_ring_dma); /* Enable TX and RX */ - macb_writel(bp, NCR, MACB_BIT(RE) | MACB_BIT(TE) | MACB_BIT(MPE)); + macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(RE) | MACB_BIT(TE)); /* Enable interrupts */ macb_writel(bp, IER, (MACB_RX_INT_FLAGS