From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Walker Subject: Re: gianfar: Implement MAC reset and reconfig procedure Date: Tue, 16 Oct 2018 14:36:29 -0700 Message-ID: <20181016213629.mjgrkifpt265hvvm@zorba> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Hemant Ramdasi , netdev@vger.kernel.org To: Claudiu Manoil Return-path: Received: from rcdn-iport-3.cisco.com ([173.37.86.74]:58160 "EHLO rcdn-iport-3.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726048AbeJQFiT (ORCPT ); Wed, 17 Oct 2018 01:38:19 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: Hi, I would like to report an issue in the gianfar driver. The issue is as follows. We have a P2020 board that uses the gianfar driver, and we have a m88e1101 PHY connect. When the interface is initially brought up traffic flows as normal. If you take the interface down then bring it back up traffic stops flowing. If you do this sequence over and over up/down/up we find that the interface will allow traffic to flow at a low percentage. In v4.9 interface allows traffic about %10 of the time. In v4.19-rc8 the allows traffic %30 of the time. After bisecting I found that in v3.14 the interface was rock solid and never did we see this issue. However, v3.15 we started to see this issue. After bisecting I found the following change is the first one which causes the issue, a328ac9 gianfar: Implement MAC reset and reconfig procedure I was able to revert this in v3.15 , however with later development a revert doesn't appear to be possible. We have no fix for this currently. I can do testing if you have an idea what might cause the issue. Daniel