cpufreq: amd-pstate: fix the highest frequency issue which limits performance
authorPerry Yuan <perry.yuan@amd.com>
Wed, 8 May 2024 05:47:03 +0000 (13:47 +0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 8 May 2024 11:56:00 +0000 (13:56 +0200)
commitbf202e654bfa57fb8cf9d93d4c6855890b70b9c4
tree6f8c4c9d940b63de8da81d8ab22a64690413e301
parent0a206fe35d360a9ec1c8b1609ca394c2759a8962
cpufreq: amd-pstate: fix the highest frequency issue which limits performance

To address the performance drop issue, an optimization has been
implemented. The incorrect highest performance value previously set by the
low-level power firmware for AMD CPUs with Family ID 0x19 and Model ID
ranging from 0x70 to 0x7F series has been identified as the cause.

To resolve this, a check has been implemented to accurately determine the
CPU family and model ID. The correct highest performance value is now set
and the performance drop caused by the incorrect highest performance value
are eliminated.

Before the fix, the highest frequency was set to 4200MHz, now it is set
to 4971MHz which is correct.

CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ       MHZ
  0    0      0    0 0:0:0:0          yes 4971.0000 400.0000  400.0000
  1    0      0    0 0:0:0:0          yes 4971.0000 400.0000  400.0000
  2    0      0    1 1:1:1:0          yes 4971.0000 400.0000 4865.8140
  3    0      0    1 1:1:1:0          yes 4971.0000 400.0000  400.0000

Fixes: f3a052391822 ("cpufreq: amd-pstate: Enable amd-pstate preferred core support")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218759
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Gaha Bana <gahabana@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/cpufreq/amd-pstate.c