Re: [PATCH 2/2] arm64: dts: realtek: Add RTD1319 SoC and Realtek PymParticle EVB

From: Robin Murphy
Date: Thu Dec 05 2019 - 07:10:41 EST


On 2019-12-05 10:58 am, Andreas FÃrber wrote:
[...]
+ arm_pmu: pmu {
+ compatible = "arm,armv8-pmuv3";
+ interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW>;
+ interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>,
+ <&cpu3>;
+ };

@Robin, is this single PPI interrupt better than previous single SPI?

Yes, a PPI is ideal (since it allows core to see its own local interrupt).

Is "arm,armv8-pmuv3" the correct one to use for Cortex-A55? There's no
"arm,cortex-a55-pmu" binding - is that still in the works?

Hmm, I had thought that had been done already, but apparently not. Looks like it's high time for another round of event map updates for the latest Cortex and Neoverse cores, so I guess I'll add that to our backlog internally - although the PMU events should be in the public TRMs so if anyone else *did* fancy ploughing through them to spin patches they're always welcome to :)

In the meantime the generic PMUv3 compatible will at least expose the subset of mandatory architectural events, which is arguably more useful than nothing.

+
+ psci {
+ compatible = "arm,psci-1.0";

@Lorenzo: Same question as left unanswered for RTD1619:
Should this be "arm,psci-1.0", "arm-psci-0.2"?

The YAML schema allows both, without clearly documenting which one shall
be used in new DTs, and there's no psci-1.0 example either.

FWIW the age of the DT shouldn't really be relevant - it's a question of whether the platform's EL3 firmware actually implements the PSCI 1.0 (or later) spec, or is some fossilised binary based on the older version.

Robin.