Re: [PATCH v3 2/4] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: "Pali Rohár" <pali@kernel.org>, "Rob Herring" <robh+dt@kernel.org>
Cc: "Bjorn Helgaas" <bhelgaas@google.com>,
	"Andrew Lunn" <andrew@lunn.ch>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Marek Behún" <kabel@kernel.org>,
	"Russell King" <rmk+kernel@armlinux.org.uk>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/4] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property
Date: Fri, 8 Apr 2022 11:31:52 +0100	[thread overview]
Message-ID: <YlAPGCSQraPJA3bV@lpieralisi> (raw)
In-Reply-To: <20220325093827.4983-3-pali@kernel.org>

On Fri, Mar 25, 2022 at 10:38:25AM +0100, Pali Rohár wrote:
> This property specifies slot power limit in mW unit. It is a form-factor
> and board specific value and must be initialized by hardware.
> 
> Some PCIe controllers delegate this work to software to allow hardware
> flexibility and therefore this property basically specifies what should
> host bridge program into PCIe Slot Capabilities registers.
> 
> The property needs to be specified in mW unit instead of the special format
> defined by Slot Capabilities (which encodes scaling factor or different
> unit). Host drivers should convert the value from mW to needed format.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> 
> ---
> This change was already accepted into dt-schema repo by Rob Herring:
> https://github.com/devicetree-org/dt-schema/pull/66

Is there a way I can check a DT binding was pulled into the schema
without having to read the patch (eg just checking Rob's Acked/Reviewed
tags ?)

I think this patch should have been posted to
devicetree@vger.kernel.org, by the way.

Lorenzo

>  Documentation/devicetree/bindings/pci/pci.txt | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> index 6a8f2874a24d..b0cc133ed00d 100644
> --- a/Documentation/devicetree/bindings/pci/pci.txt
> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> @@ -32,6 +32,12 @@ driver implementation may support the following properties:
>     root port to downstream device and host bridge drivers can do programming
>     which depends on CLKREQ signal existence. For example, programming root port
>     not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal.
> +- slot-power-limit-milliwatt:
> +   If present, this property specifies slot power limit in milliwatts. Host
> +   drivers can parse this property and use it for programming Root Port or host
> +   bridge, or for composing and sending PCIe Set_Slot_Power_Limit messages
> +   through the Root Port or host bridge when transitioning PCIe link from a
> +   non-DL_Up Status to a DL_Up Status.
>  
>  PCI-PCI Bridge properties
>  -------------------------
> -- 
> 2.20.1
> 