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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9497AC433EF for ; Sun, 10 Jul 2022 14:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229482AbiGJOSE (ORCPT ); Sun, 10 Jul 2022 10:18:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229470AbiGJOSE (ORCPT ); Sun, 10 Jul 2022 10:18:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F27FEDF4B for ; Sun, 10 Jul 2022 07:18:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8EA88611E1 for ; Sun, 10 Jul 2022 14:18:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2D57C3411E; Sun, 10 Jul 2022 14:18:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657462682; bh=eV7eKDx9Qy4jDuznrj9Up/xU5ON7WlAvgN3pikH1b10=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WAH5pvJJhOm3d8/siwTIHqxn7WRYE7X8N0zLgy460/an5T/X1onGKgn0HexFe7i74 VxKS9nMlo9T4bs8V+UjPhiiH4OYI4QAODNL7orvZZV/KNGzUU2CJe+xX3q3T5jKR+3 /rrTucqNc05E2tk6geFFYpA0EvRKbF4fOG/qjzmg= Date: Sun, 10 Jul 2022 16:17:59 +0200 From: Greg KH To: Christian Marangi Cc: stable@vger.kernel.org, Jakub Kicinski Subject: Re: [PATCH] net: dsa: qca8k: reset cpu port on MTU change Message-ID: References: <20220628143010.17526-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220628143010.17526-1-ansuelsmth@gmail.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Jun 28, 2022 at 04:30:10PM +0200, Christian Marangi wrote: > commit 386228c694bf1e7a7688e44412cb33500b0ac585 upstream. > > It was discovered that the Documentation lacks of a fundamental detail > on how to correctly change the MAX_FRAME_SIZE of the switch. > > In fact if the MAX_FRAME_SIZE is changed while the cpu port is on, the > switch panics and cease to send any packet. This cause the mgmt ethernet > system to not receive any packet (the slow fallback still works) and > makes the device not reachable. To recover from this a switch reset is > required. > > To correctly handle this, turn off the cpu ports before changing the > MAX_FRAME_SIZE and turn on again after the value is applied. > > Fixes: f58d2598cf70 ("net: dsa: qca8k: implement the port MTU callbacks") > Cc: stable@vger.kernel.org > Signed-off-by: Christian Marangi > Link: https://lore.kernel.org/r/20220621151122.10220-1-ansuelsmth@gmail.com > Signed-off-by: Jakub Kicinski > [ backport: fix conflict using the old port_sts struct instead of bitmap ] > --- > drivers/net/dsa/qca8k.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) This only applied to 5.15.y and 5.18.y, what about 5.10.y? Please give us a hint as to what kernel(s) a backport is for when sending them. thanks, greg k-h