Re: [PATCH v4 3/9] drm: verisilicon: add a driver for Verisilicon display controllers

From: "Luca Ceresoli" <luca.ceresoli@bootlin.com>
To: "Icenowy Zheng" <zhengxingda@iscas.ac.cn>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Simona Vetter" <simona@ffwll.ch>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Drew Fustini" <fustini@kernel.org>,
	"Guo Ren" <guoren@kernel.org>, "Fu Wei" <wefu@redhat.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Andrzej Hajda" <andrzej.hajda@intel.com>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Robert Foss" <rfoss@kernel.org>,
	"Laurent Pinchart" <Laurent.pinchart@ideasonboard.com>,
	"Jonas Karlman" <jonas@kwiboo.se>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Michal Wilczynski" <m.wilczynski@samsung.com>
Cc: devicetree@vger.kernel.org, Yao Zi <ziyao@disroot.org>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Han Gao <rabenda.cn@gmail.com>,
	linux-riscv@lists.infradead.org
Subject: Re: [PATCH v4 3/9] drm: verisilicon: add a driver for Verisilicon display controllers
Date: Wed, 31 Dec 2025 15:20:19 +0100	[thread overview]
Message-ID: <DFCGV315JITK.1TXTXWUOMLMB9@bootlin.com> (raw)
In-Reply-To: <20251224161205.1132149-4-zhengxingda@iscas.ac.cn>

On Wed Dec 24, 2025 at 5:11 PM CET, Icenowy Zheng wrote:
> From: Icenowy Zheng <uwu@icenowy.me>
>
> This is a from-scratch driver targeting Verisilicon DC-series display
> controllers, which feature self-identification functionality like their
> GC-series GPUs.
>
> Only DC8200 is being supported now, and only the main framebuffer is set
> up (as the DRM primary plane). Support for more DC models and more
> features is my further targets.
>
> As the display controller is delivered to SoC vendors as a whole part,
> this driver does not use component framework and extra bridges inside a
> SoC is expected to be implemented as dedicated bridges (this driver
> properly supports bridge chaining).
>
> Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>

[...]

> +++ b/drivers/gpu/drm/verisilicon/vs_bridge.h

> +struct vs_bridge {
> +	struct drm_bridge base;
> +	struct drm_encoder *enc;
> +	struct drm_connector *conn;
> +
> +	struct vs_crtc *crtc;
> +	struct drm_bridge *next;

It is a common convention to call this 'next_bridge'. This makes it easier
to understand but also to grep and find similar patterns.

For info, we are working to move to 'struct drm_bridge::next_bridge' [0] as
you can see from example patches like [1]. However this currently applies
only to drivers using of_drm_find_bridge(), so it does not affect your
driver.

I'm sorry I have seen your patch only at v4.

[0] https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/3fdeae134ba956aacbd87d5532c025913c98fc49
[1] https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/8f92a5fcbfe33f86b08f5f74dcc58a41425ea8c0

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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