From mboxrd@z Thu Jan 1 00:00:00 1970 From: Markus Brunner Subject: Re: [PATCH] drivers: net: cpsw: fix RMII/RGMII mode when used with fixed-link PHY Date: Wed, 16 Dec 2015 07:39:16 +0100 Message-ID: <1741588.Ve76Z1ZI87@localhost> References: <20151209223115.6c5a400f.drivshin.allworx@gmail.com> <6416396.ZOturxhSar@localhost> <20151214130446.1e14fbb8.drivshin.allworx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, David Miller , Mugunthan V N , Pascal Speck , Daniel Trautmann To: "David Rivshin (Allworx)" Return-path: Received: from mail-wm0-f43.google.com ([74.125.82.43]:34277 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932197AbbLPGlO (ORCPT ); Wed, 16 Dec 2015 01:41:14 -0500 In-Reply-To: <20151214130446.1e14fbb8.drivshin.allworx@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Monday 14 December 2015 13:04:46 David Rivshin wrote: > On Sat, 12 Dec 2015 16:44:19 +0100 ... > > Your patch works fine on my board, which uses MII and dual_emac with > > a fixed_phy and a real one. > > Thanks for checking. The only dual_emac board I have available is the > EVMSK, which has two real PHYs. I'm not sure of the usual etiquette > (and Google was unhelpful), should I add a Tested-by on the next > version? > Yes you can. Documentation/SubmittingPatches has some notes about it. > > > Besides fixing the bug mentioned in the commit log, there are a few > > > > > > other differences to note: > > > * If both "phy_id" and a "fixed-link" subnode are present this > > > > > > patch will use the "phy_id" property. This should preserve current > > > behavior with existing devicetrees that might incorrectly have > > > both. This motivates the biggest difference in code organization > > > from 1f71e8c96fc6. > > > > > > * Some error messages have been tweaked to reflect the slightly > > > > > > changed meanings of the checks. > > > > I wanted to keep changes small and didn't spend too much thinking > > about already broken devicetrees. Since my patch is quite new, I > > I'm honestly not sure it's an important consideration myself. Most > patches I've seen in this area for this or other drivers do not take > such behavior into account (e.g. the phy-handle parsing that went in > to cpsw in 4.3). > I would generally feel more comfortable with such a behavior tweak > (minor as it is) before 4.4 is released, to avoid ping-ponging the > behavior. But given how far along the cycle is, I'm not sure about > the chances of that. > Well I don't think compatibility for flawed DTs is such a high priority, especially if it is that unlikely that there are some affected. Keep the focus on the other _real_ problems you have encountered and fix those like you see fit. > > don't see any problems with subtle changes like that. However you > > should update the documentation as well. > > Your patch already updated .../bindings/net/cpsw.txt, which this > patch left alone. Are you referring to some other documentation, > or do you think I should update the binding documentation to state > that phy_id takes precedence over fixed-link? I figured that such > devicetrees were still officially malformed, so I thought the > existing text was appropriate. "Either the properties phy_id and phy-mode, or the sub-node fixed-link can be specified" One flaw of my patch was to ignore the phy-mode for a fixed link. Do not mention the precedence of the phy_id, because it is an undefined behavior. Your patch should change it to: "Either the property phy_id, or the sub-node fixed-link can be specified"