From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2001:4f8:3:36:211:85ff:fe63:a549]) by lists.ozlabs.org (Postfix) with ESMTP id D808B1A001D for ; Tue, 26 Jan 2016 05:47:31 +1100 (AEDT) Date: Mon, 25 Jan 2016 10:47:28 -0800 (PST) Message-Id: <20160125.104728.1314622892837934779.davem@davemloft.net> To: martin.roth@motorolasolutions.com Cc: pantelis.antoniou@gmail.com, vbordug@ru.mvista.com, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] 82xx: FCC: Fixing a bug causing to FCC port lock-up (second try) From: David Miller In-Reply-To: <1453589779-13187-1-git-send-email-martin.roth@motorolasolutions.com> References: <1453589779-13187-1-git-send-email-martin.roth@motorolasolutions.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Martin Roth Date: Sun, 24 Jan 2016 00:56:19 +0200 > This is an additional patch to the one already submitted recently. > The previous patch was not complete, and the FCC port lock-up scenario > has been reproduced in lab. > I had an opportunity to check the current patch in lab and the FCC > port lock no longer freezes, while the previous patch still locks-up the > FCC port. > The current patch fixes a pointer arithmetic bug (second bug in the same > line), which leads FCC port lock-up during underrun/collision handling. > Within the tx_startup() function in mac-fcc.c, the address of last BD is > not calculated correctly. As a result of wrong calculation of the last BD > address, the next transmitted BD may be set to an area out of the transmit > BD ring. This actually causes to port lock-up and it is not recoverable. > > Signed-off-by: Martin Roth Applied, thank you.