From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 3/3] stmmac: fix Transmit Underflow error Date: Mon, 11 Apr 2011 12:56:39 -0700 (PDT) Message-ID: <20110411.125639.104063930.davem@davemloft.net> References: <1302513406-3758-1-git-send-email-peppe.cavallaro@st.com> <1302513406-3758-3-git-send-email-peppe.cavallaro@st.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: peppe.cavallaro@st.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:53189 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755768Ab1DKT5P (ORCPT ); Mon, 11 Apr 2011 15:57:15 -0400 In-Reply-To: <1302513406-3758-3-git-send-email-peppe.cavallaro@st.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Giuseppe CAVALLARO Date: Mon, 11 Apr 2011 11:16:46 +0200 > On some old MAC chips without COE sometime the > Transmit Underflow error is issued. > > The driver aborted all the transmission process > and initialized it from scratch. > This breaks the network activity as raised by Nachiketa > on a SPEAr board. > > The patch is to fix this rare underflow event. > The driver will only clear the interrupt and the Tx > DMA will go out the Suspend state as soon as the > descriptor is fetched again. > The driver will continue to bump-up the DMA FIFO threshold > that, indeed, helped somebody to prevent this kind of error > in the past as well. > > Reported-by: Nachiketa Prachanda > Signed-off-by: Giuseppe Cavallaro Applied.