cpufreq: amd-pstate: get transition delay and latency value from ACPI tables
authorPerry Yuan <perry.yuan@amd.com>
Thu, 25 Apr 2024 08:07:56 +0000 (16:07 +0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 26 Apr 2024 17:35:38 +0000 (19:35 +0200)
commit069a2bb8c48c43176f2f0e6cae5efe2f39f6bdf2
tree2881e496f2a701c24f18c4c9e97f2ed3a52c3067
parent2ddb8a3946d4d02115b2dca53c5493ff00536002
cpufreq: amd-pstate: get transition delay and latency value from ACPI tables

Make pstate driver initially retrieve the P-state transition delay and
latency values from the BIOS ACPI tables which has more reasonable
delay and latency values according to the platform design and
requirements.

Previously there values were hardcoded at specific value which may
have conflicted with platform and it might not reflect the most
accurate or optimized setting for the processor.

[054h 0084   8]                Preserve Mask : FFFFFFFF00000000
[05Ch 0092   8]                   Write Mask : 0000000000000001
[064h 0100   4]              Command Latency : 00000FA0
[068h 0104   4]          Maximum Access Rate : 0000EA60
[06Ch 0108   2]      Minimum Turnaround Time : 0000

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/cpufreq/amd-pstate.c