Re: [PATCH v11 2/7] MIPS: Loongson64: dts: introduce ls3A4000 evaluation board

From: Rob Herring <robh@kernel.org>
To: Sui Jingfeng <15330273260@189.cn>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Roland Scheidegger <sroland@vmware.com>,
	Zack Rusin <zackr@vmware.com>,
	Christian Gmeiner <christian.gmeiner@gmail.com>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>,
	Sam Ravnborg <sam@ravnborg.org>,
	"David S . Miller" <davem@davemloft.net>,
	Lucas Stach <l.stach@pengutronix.de>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Ilia Mirkin <imirkin@alum.mit.edu>,
	Qing Zhang <zhangqing@loongson.cn>,
	suijingfeng <suijingfeng@loongson.cn>,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v11 2/7] MIPS: Loongson64: dts: introduce ls3A4000 evaluation board
Date: Wed, 23 Mar 2022 07:53:07 -0500	[thread overview]
Message-ID: <YjsYM0M24VhkCHwG@robh.at.kernel.org> (raw)
In-Reply-To: <abe784ce-eb9e-0143-dbc3-d415bbedbb81@189.cn>

On Wed, Mar 23, 2022 at 09:53:14AM +0800, Sui Jingfeng wrote:
> 
> On 2022/3/23 00:06, Jiaxun Yang wrote:
> > 
> > 
> > 在 2022/3/22 13:38, Sui Jingfeng 写道:
> > > 
> > > On 2022/3/22 21:05, Jiaxun Yang wrote:
> > > > 
> > > > 
> > > > 在 2022/3/21 16:29, Sui Jingfeng 写道:
> > > > > From: suijingfeng <suijingfeng@loongson.cn>
> > > > > 
> > > > > The board name is LS3A4000_7A1000_EVB_BOARD_V1.4, it consist of 1.8Ghz
> > > > > mips64r5 4-core CPU and LS7A1000 bridge chip. It has PCIe
> > > > > GEN2 x8 slot,
> > > > > therefore can play with discrete graphics card.
> > > > 
> > > > Hi Jingfeng,
> > > > 
> > > > As we've discussed before if you are going to introduce new dts
> > > > then you *MUST*
> > > > include it in makefile and wire it up in code.
> > > > 
> > > > A dts file doing nothing lying in the tree is just suspicious.
> > > > 
> > > > Thanks.
> > > > - Jiaxun
> > > > 
> > > Hi, Jiaxun,
> > > 
> > > I know what you means, but it is the kernel side developer's job.
> > > I am just a naive graphic driver developer,I can not care so much.
> > > Below is my private patch which can be used to built specific dts
> > > into the linux kernel, therefore make the verification easier.
> > Hi Jingfeng,
> > 
> > In kernel world we take care all the stuff we touched ourself :-)
> > 
> > If you are not confident with them please drop those DTS from the
> > patchset
> > besides the generic one. I can do the rest for you after getting this
> > set merged.
> > 
> > Thanks.
> > - Jiaxun
> > 
> Hi, Jiaxun
> 
> Build all dts into vmlinuz will make the vmlinuz bigger and bigger.
> How does the kernel get the dtb is another big issue, either from built-in
> dtb or pass from the firmware(pmon and uefi etc). This should be
> solved with another patch carefully. Providing board specific dts
> helps to code review, it helps reviewers understand that there are
> variant boards and have to be express with different OF graph.

Built-in DTBs are for legacy bootloaders that don't understand DT. I 
would not expect a new platform to need this.

> 
> Now, there are about 6 dts under arch/mips/boot/dts/loongson/,
> Suppose loongson have 1000+ different board, do you want built all
> of them into vmlinuz?

The point was to add the .dts to Makefile so it builds, not so it is 
built-in. How are you testing those build with dtc and dtschema if not 
added to kbuild?

Rob