Re: [PATCH v2 2/4] dt-bindings: usb: mtk-xhci: Make all clocks required

From: Rob Herring <robh@kernel.org>
To: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>,
	kernel@collabora.com,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-usb@vger.kernel.org
Subject: Re: [PATCH v2 2/4] dt-bindings: usb: mtk-xhci: Make all clocks required
Date: Fri, 1 Jul 2022 15:37:02 -0600	[thread overview]
Message-ID: <20220701213702.GA1591697-robh@kernel.org> (raw)
In-Reply-To: <20220629185546.z6rn7xp3ejpmaupi@notapiano>

On Wed, Jun 29, 2022 at 02:55:46PM -0400, Nícolas F. R. A. Prado wrote:
> On Tue, Jun 28, 2022 at 08:57:45AM +0800, Chunfeng Yun wrote:
> > Hi Nícolas,
> > 
> > On Thu, 2022-06-23 at 15:37 -0400, Nícolas F. R. A. Prado wrote:
> > > All of the clocks listed in the binding are always wired to the XHCI
> > > controller hardware blocks on all SoCs. The reason some clocks were
> > > made
> > > optional in the binding was to account for the fact that depending on
> > > the SoC, some of the clocks might be fixed (ie not controlled by
> > > software).
> > > 
> > > Given that the devicetree should represent the hardware, make all
> > > clocks
> > > required in the binding. Subsequent patches will make the DTS changes
> > > to
> > > specify fixed-clocks for the clocks that aren't controllable.
> > > 
> > > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
> > > 
> > > ---
> > > 
> > > Changes in v2:
> > > - Undid clock list changes that allowed middle clocks to be missing
> > > from
> > >   v1 and made all clocks required instead
> > > - Rewrote commit message and title
> > > 
> > >  Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml | 4 +
> > > ---
> > >  1 file changed, 1 insertion(+), 3 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml
> > > index 63cbc2b62d18..1444d18ef9bc 100644
> > > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > > @@ -67,7 +67,6 @@ properties:
> > >      maxItems: 1
> > >  
> > >    clocks:
> > > -    minItems: 1
> > >      items:
> > >        - description: Controller clock used by normal mode
> > >        - description: Reference clock used by low power mode etc
> > > @@ -76,9 +75,8 @@ properties:
> > >        - description: controller clock
> > >  
> > >    clock-names:
> > > -    minItems: 1
> > >      items:
> > > -      - const: sys_ck  # required, the following ones are optional
> > > +      - const: sys_ck
> > >        - const: ref_ck
> > >        - const: mcu_ck
> > >        - const: dma_ck
> > 
> > This patch causes more check warning, I prefer to leave dt-bindings
> > unchanged, but just fix mt8195's dts warning instead, thanks a lot
> 
> Hi Chunfeng,
> 
> the warnings reported by Rob's bot only happen if patches 3 and 4 aren't applied
> to adapt the devicetrees. They are ABI breaking changes, but I understood this
> as the desired solution from the discussion we had with Krzysztof on v1 [1].

The warnings have nothing to do with patches 3 and 4 as those are for 
dts files. It's examples in bindings that are the problem.

Rob