Re: [PATCH 3/9] arm64: dts: rockchip: Prepare Rockchip RK1808

From: "Andreas Färber" <afaerber@suse.de>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-rockchip@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	Heiko Stuebner <heiko@sntech.de>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH 3/9] arm64: dts: rockchip: Prepare Rockchip RK1808
Date: Mon, 24 May 2021 15:32:41 +0200	[thread overview]
Message-ID: <7ef183f1-00f8-13c4-1fd3-eae9e0bbf74c@suse.de> (raw)
In-Reply-To: <87h7j1vhq7.wl-maz@kernel.org>

On 17.05.21 11:21, Marc Zyngier wrote:
> On Mon, 17 May 2021 00:05:45 +0100,
> Andreas Färber <afaerber@suse.de> wrote:
>>
>> Add an initial Device Tree for Rockchip RK1808 SoC.
>> Based on shipping TB-RK1808M0 DTB.
>>
>> Signed-off-by: Andreas Färber <afaerber@suse.de>
>> ---
>>  arch/arm64/boot/dts/rockchip/rk1808.dtsi | 203 +++++++++++++++++++++++
>>  1 file changed, 203 insertions(+)
>>  create mode 100644 arch/arm64/boot/dts/rockchip/rk1808.dtsi
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk1808.dtsi b/arch/arm64/boot/dts/rockchip/rk1808.dtsi
>> new file mode 100644
>> index 000000000000..af2b51afda7d
>> --- /dev/null
>> +++ b/arch/arm64/boot/dts/rockchip/rk1808.dtsi
[...]
>> +		gic: interrupt-controller@ff100000 {
>> +			compatible = "arm,gic-v3";
>> +			reg = <0xff100000 0x10000>, /* GICD */
>> +			      <0xff140000 0xc0000>, /* GICR */
> 
> This is obviously wrong. You have two CPUs, and yet describe a range
> that spans 6. I guess this is a copy paste from rk3399 again?

Not on my part at least. As indicated, these numbers are what ships in
the DTB on the RK1808 card, as per dtc -I dtb -O dts. Could be a mistake
by Rockchip, of course.

Are you suggesting 0xc0000/6*2 = 0x40000 for two CPUs here?
Works as bad as before - investigation still ongoing with latest next.

As for "obviously": The GICv3 YAML binding has no description for me to
validate those numbers: "GIC Redistributors (GICR), one range per
redistributor region" - says nothing about correlation to number of CPUs
or size per CPU, and the examples are not explaining either: 0x200000
has no number of CPUs associated, and by my calculation 0x800000 for 32
CPUs results in 0x40000 per CPU; but then again the examples also have
GICC etc. at diverging 0x2000 size.

>> +			      <0xff300000 0x10000>, /* GICC */
>> +			      <0xff310000 0x10000>, /* GICH */
>> +			      <0xff320000 0x10000>; /* GICV */
>> +			interrupt-controller;
>> +			#interrupt-cells = <3>;
>> +			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
>> +			#address-cells = <1>;
>> +			#size-cells = <1>;
>> +			ranges;
>> +
>> +			gic_its: msi-controller@ff120000 {
>> +				compatible = "arm,gic-v3-its";
>> +				reg = <0xff120000 0x20000>;
>> +				msi-controller;
>> +				#msi-cells = <1>;
>> +			};
> 
> What uses the ITS?

DT-wise seemingly only the __symbols__ table (named just "its" there, I
notice), so we could drop (or rename) the label if you prefer.

Regards,
Andreas

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