From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net: smsc911x: Reset PHY during initialization Date: Sun, 01 Nov 2015 16:51:51 -0500 (EST) Message-ID: <20151101.165151.1119828043753664843.davem@davemloft.net> References: <1446188779-4184-1-git-send-email-p.fedin@samsung.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, steve.glendinning@shawell.net To: p.fedin@samsung.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:55368 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752741AbbKAVvx (ORCPT ); Sun, 1 Nov 2015 16:51:53 -0500 In-Reply-To: <1446188779-4184-1-git-send-email-p.fedin@samsung.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Pavel Fedin Date: Fri, 30 Oct 2015 10:06:19 +0300 > On certain hardware after software reboot the chip may get stuck and fail > to reinitialize during reset. This can be fixed by ensuring that PHY is > reset too. > > Old PHY resetting method required operational MDIO interface, therefore > the chip should have been already set up. In order to be able to function > during probe, it is changed to use PMT_CTRL register. > > The problem could be observed on SMDK5410 board. > > Signed-off-by: Pavel Fedin I'm pretty sure this is going to break the PHY loopback test. This is such a tricky and fragile area to get right, therefore I want you to specifically guard any change in how PHY reset is done with tests against the specific chips that have the problem. Furthermore, I want you to test whether this has any negative effects on the PHY loopback test.