From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v2 2/4] dt-bindings: memory: Add binding for NVIDIA Tegra30 External Memory Controller Date: Wed, 1 May 2019 19:17:03 -0500 Message-ID: References: <20190414202009.31268-1-digetx@gmail.com> <20190414202009.31268-3-digetx@gmail.com> <20190429220542.GA17924@bogus> <137c766e-66f6-828a-5c3b-f526d66d37bd@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <137c766e-66f6-828a-5c3b-f526d66d37bd@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko Cc: Mark Rutland , Peter De Schrijver , Prashant Gaikwad , Michael Turquette , Stephen Boyd , Thierry Reding , Jonathan Hunter , Joseph Lo , devicetree@vger.kernel.org, linux-clk , linux-tegra@vger.kernel.org, "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On Wed, May 1, 2019 at 7:06 PM Dmitry Osipenko wrote: > > 30.04.2019 1:05, Rob Herring =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > > On Sun, Apr 14, 2019 at 11:20:07PM +0300, Dmitry Osipenko wrote: > >> Add device-tree binding for NVIDIA Tegra30 External Memory Controller. > >> The binding is based on the Tegra124 EMC binding since hardware is > >> similar, although there are couple significant differences. > > > > My comments on Tegra124 binding apply here. > > The common timing definition doesn't fully match the definition that is > used by Tegra's Memory Controller, thus the DQS (data strobe) timing > parameter is comprised of multiple sub-parameters that describe how to > generate the strobe in hardware. There are also more additional > parameters that are specific to Tegra and they are individually > characterized for each memory model and clock rate. Hence the common > timing definition isn't usable. I don't understand. Every PC in the world can work with any DIMM (within a given generation) just with SPD data. Why is that not sufficient here? In any case, it seems for Tegra124 a different approach is going to be taken. Seems like an "avoid DT" solution to me, but if it's contained within the firmware it's not my problem. Rob