Hi Tanmay
On 25/03/2024 05:30, Tanmay Jagdale wrote:
Hi Anshuman,
On 2024-03-14 at 11:28:32, Anshuman Khandual (anshuman.khandual@arm.com) wrote:
This moves remaining AMBA ACPI devices into respective platform drivers for enabling ACPI based power management support. This series applies on latest coresight next. This series has been built, and boot tested on a DT based (RB5) and ACPI supported coresight platform (N1SDP).
I have tested this patch series on Marvell platform with ACPI and DT support.
On platforms that have a dedicated sink (ETF/ETR) for every source, when we boot with fewer cores, the per-core sinks (ETF/ETR) are still probed successfully.
Thank you for testing, could we add your Tested-by: tag to the series ?
Ansuhman, Suzuki, James,
Would be helpful if we add a notion of associated CPU to the TMC core driver? So that, if the associated CPU is powered off, the TMC ETF/ETR device would not be probed.
Doing this in a generic way (i.e., "not probing" devices with missing devices is complicated). What exactly is the concern here ? "power consumption" or "devices that cannot be used without the source devices" ?
We already have a concept of "orphan" devices (i.e., with missing connection links). But we need the devices probed to have this information!
How are these CPUs connected to the TMC ? are there any funnels/links in between them ? If we have to walk the connection link up the trace path, that could be complicated.
The best we could do is expose if a device is still orphan or not via sysfs. I guess that doesn't take us anywhere much.
Suzuki
With Regards, Tanmay
https://git.gitlab.arm.com/linux-arm/linux-anshuman.git (amba_other_acpi_migration_v7)
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