Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 18 Nov 2022 12:08:08 -0600
From:   Nishanth Menon <nm@ti.com>
To:     Andrew Davis <afd@ti.com>
CC:     Apurva Nandan <a-nandan@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Tero Kristo <kristo@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-gpio@vger.kernel.org>, Hari Nagalla <hnagalla@ti.com>
Subject: Re: [PATCH v3 4/4] arm64: dts: ti: Add support for J784S4 EVM board
Message-ID: <20221118180808.wnel7d6gswsnooww@junkman>
References: <20221116130428.161329-1-a-nandan@ti.com>
 <20221116130428.161329-5-a-nandan@ti.com>
 <b57433e7-b309-bd1c-f794-3da74021f03c@ti.com>
 <20221118174754.y37pq77drvla2uxj@tinderbox>
 <8c123fa2-caab-d2dd-5eb4-688f1c6abb33@ti.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <8c123fa2-caab-d2dd-5eb4-688f1c6abb33@ti.com>
User-Agent: NeoMutt/20171215
Precedence: bulk

On 11:56-20221118, Andrew Davis wrote:
> On 11/18/22 11:47 AM, Nishanth Menon wrote:
> > On 11:40-20221118, Andrew Davis wrote:
> > > On 11/16/22 7:04 AM, Apurva Nandan wrote:
> > 
> > [...]
> > 
> > > > +#include <dt-bindings/net/ti-dp83867.h>
> > > > +#include <dt-bindings/gpio/gpio.h>
> > > > +#include "k3-j784s4.dtsi"
> > > > +
> > > > +/ {
> > > > +	compatible = "ti,j784s4-evm", "ti,j784s4";
> > > > +	model = "Texas Instruments J784S4 EVM";
> > > > +
> > > > +	chosen {
> > > > +		stdout-path = "serial2:115200n8";
> > > > +	};
> > > > +
> > > > +	aliases {
> > > > +		serial2 = &main_uart8;
> > > 
> > > This feels hacky. Your chosen node picks serial2 as that is usually
> > > the one that is wired up on K3 boards. But on this board it is main_uart8.
> > > So why not have this be serial10, then choose
> > > 
> > > stdout-path = "serial10:115200n8";
> > > 
> > > Also, I've made comments on previous version of this series, it is
> > > nice to include folks who have commented before in the CC for future
> > > versions, that way our filters don't hide these away and we can more
> > > easily check that our comments have been addressed.
> > 
> > Please stick with the standard of serial2 as the linux console standard.
> > We ended up with that to ease up capabilities of various distros to
> > uniformly work across SoC and board variants.
> > 
> 
> The chosen "stdout-path" is for setting the kernel's default output terminal.
> Distros and other userspaces need to use their own policy mechanisms for
> picking what serial port to run getty on or whatever the issue may be.
> 
> Some look at the kernel command line, and our bootloader provides
> that too, so still no reason to fake alias names here.


We have had this conversation earlier as well.

https://lore.kernel.org/linux-arm-kernel/CAK8P3a2VSBvOn1o+q1PYZaQ6LS9U4cz+DZGuDbisHkwNs2dAAw@mail.gmail.com/T/#m4ecb0dc6a78c84631f072faa1b0df0df46333d09

This is also the reason why we picked serial2 as linux console as a
standard across the boards based on the ecosystem.

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D