[BUG] dts: hi6220: PMU events not fully functional

[Robin Murphy]

On 2022-01-24 22:33, Carlton Shepherd wrote:
> Hello,
> 
> The perf subsystem does not detect any PMU events for the HiSilicon
> 6220 SoC. (Tested on a HiKey 620 with 5.17.0-rc1.)
> 
> Based on [1] and [2], /arch/arm64/boot/dts/hisilicon/hi6220.dtsi is
> missing a PMU node. This was patched for the hi3660 in
> /arch/arm64/boot/dts/hisilicon/hi3660.dtsi [3], but remains defective
> for the hi6220.
> 
> Could somebody please provide some assistance?

According to the SoC functional description linked from [4], the PMU 
interrupts for all the CPUs appear to be combined into a single IRQ 
line, which means we'll never be able to support it in Linux anyway.

Cheers,
Robin.

[4] 
https://www.96boards.org/documentation/consumer/hikey/hikey620/hardware-docs/

> 
> Kind regards,
> Carlton Shepherd
> 
> 1. https://www.96boards.org/documentation/consumer/hikey/hikey960/support/pmu-on-hikey960.md.html
> 2. https://discuss.96boards.org/t/linux-perf-list-failing-to-detect-hardware-events-on-hikey620/11752
> 3. https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1465696.html
> 
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