From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions Date: Sun, 13 May 2018 22:29:38 +0200 Message-ID: <20180513202938.GH12738@lunn.ch> References: <20180513191425.9801-1-wens@csie.org> <20180513191425.9801-2-wens@csie.org> <20180513194919.GE12738@lunn.ch> <20180513200529.GF12738@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org To: Chen-Yu Tsai Cc: Giuseppe Cavallaro , linux-arm-kernel , devicetree , netdev , Corentin Labbe , Icenowy Zheng , Maxime Ripard , Rob Herring List-Id: devicetree@vger.kernel.org On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote: > On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn wrote: > >> > Hi Chen-Yu > >> > > >> > Are these delays the MAC applies? Not the PHY. It would be good to > >> > make it clear here these are MAC imposed delays. > >> > >> Yes these are applied on the MAC side. Being described in the device > >> tree bindings for the MAC, I thought this was implied to be the case? > >> Are there known exceptions? > > > > There is frequent confusion with this. Most of the time, the PHY does > > the delay, not the MAC, based on the phy-mode. So the MAC doing it is > > an exception in itself. > > > > Do you actually need these delays for the board you adding support > > for? Does the PHY not support adding the needed delays? If you don't > > need the delays, i would not even implement them. > > Yes this is already used on the Bananapi M3. This patch merely reformats > the description and adds a note saying this only applies to RGMII mode. Yes, the current code is needed for the Bananapi M3. But you have another patch which extends the code to support a smaller range. Do you have a board which actually needs this? If not, i would not add that new code. Andrew