Re: [PATCH 1/8] dt-bindings: sun6i-a31-mipi-dphy: Add the interrupts property

From: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
To: Samuel Holland <samuel@sholland.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Vinod Koul <vkoul@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Maxime Ripard <mripard@kernel.org>,
	Jagan Teki <jagan@amarulasolutions.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Maxime Ripard <maxime@cerno.tech>,
	Rob Herring <robh+dt@kernel.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org,
	linux-sunxi@lists.linux.dev
Subject: Re: [PATCH 1/8] dt-bindings: sun6i-a31-mipi-dphy: Add the interrupts property
Date: Tue, 27 Sep 2022 11:36:02 +0200	[thread overview]
Message-ID: <YzLEApjzpGaDxKni@aptenodytes> (raw)
In-Reply-To: <YzFwst0GpdRBx/9l@aptenodytes>

[-- Attachment #1: Type: text/plain, Size: 1887 bytes --]

Hi,

On Mon 26 Sep 22, 11:28, Paul Kocialkowski wrote:
> Hi Samuel,
> 
> On Fri 12 Aug 22, 17:19, Samuel Holland wrote:
> > On 8/12/22 5:45 AM, Krzysztof Kozlowski wrote:
> > > On 12/08/2022 10:55, Samuel Holland wrote:
> > >> The sun6i DPHY can generate several interrupts, mostly for reporting
> > >> error conditions, but also for detecting BTA and UPLS sequences.
> > >> Document this capability in order to accurately describe the hardware.
> > >>
> > >> The DPHY has no interrupt number provided in the vendor documentation
> > >> because its interrupt line is shared with the DSI controller.
> > >>
> > >> Fixes: c25b84c00826 ("dt-bindings: display: Convert Allwinner DSI to a schema")
> > > 
> > > I don't understand what is being fixed in that commit. That commit did
> > > not have interrupts in D-PHY, so what was broken by it?
> > > 
> > > The Fixes tag annotates the commit which introduced a bug.
> > 
> > The binding had a bug because it did not accurately describe the hardware.
> 
> [...]
> 
> Coming back to this series, I don't really get the point of introducing the
> interrupt in the bindings and the device-tree sources if the interrupt is not
> required for normal operation. I would just drop it.
> 
> I recall I was in the same situation for the MIPI CSI-2 controllers, which also
> have a dedicated interrupt but only useful for debugging/error reporting.
> I was asked not to introduce it back then, so I suppose the same should apply.

Coming back to this, my memories were wrong and the interrupt was in fact added
to the binding and the dt description.

Nevermind my previous comment, I guess it does make sense to have it in the dt
hardware description even if the driver does not use it.

Sorry for the noise,

Paul

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]