Hi Srinivas, Thank you for your reply.

On Tue, Sep 7, 2021 at 9:01 AM Srinivas Pandruvada
[off-list ref] wrote:

On Tue, 2021-09-07 at 08:45 -0700, Doug Smythies wrote:

quoted

Recent ASUS BIOS updates have changed the default system
response for this old thread, rendering "intel_pstate=no_hwp"
useless.

It also raises a question: If BIOS has forced HWP, then how do we
prevent the acpi-cpufreq driver from being used? Read on.

Does BIOS has option to enable Intel speed shift with no legacy
support?
Then this option will not populate ACPI _PSS table.

The option is there no matter what.
I have tried every variation of legacy or no legacy that
I can find. Currently:
Current boot mode:   UEFI Firmware mode
SecureBoot:          disabled

quoted

On Fri, May 14, 2021 at 3:12 PM Doug Smythies [off-list ref]
wrote:

quoted

On Fri, May 14, 2021 at 1:33 PM Giovanni Gherdovich <
ggherdovich@suse.cz> wrote:

quoted

On Fri, 2021-05-14 at 08:31 -0700, Doug Smythies wrote:

...

quoted

quoted

...

quoted

Previous correspondence was with BIOS version 1003. There have been 3
BIOS
releases since then (at least that I know of), 2103, 2201, 2301, and
all of them
have changed the behaviour of the "Auto" setting for Intel Speed
Shift
Technology BIOS setting, forcing it on upon transfer of control to
the OS.

Where with "intel_pstate=no_hwp" one used to get 0 for MSR_PM_ENABLE
(0x770) they now get 1.

So they are forcing Out of band OOB mode.
Does bit 8 or 18 in MSR 0x1aa is set?

No.

Here is the output from my msr reader/decoder program.
Kernel 5.14 (unpatched).
intel_pstate=disable
BIOS setting "Auto" for Intel Speed Shift,
Driver: acpi-cpufreq

doug@s19:~$ sudo c/msr-decoder
How many CPUs?: 12
8.) 0x198: IA32_PERF_STATUS     : CPU 0-11 :  45 :  45 :  45 :  45 :
45 :  45 :  45 :  45 :  45 :  45 :  45 :  45 :
B.) 0x770: IA32_PM_ENABLE: 1 : HWP enable
1.) 0x19C: IA32_THERM_STATUS: 88450000
2.) 0x1AA: MSR_MISC_PWR_MGMT: 401CC0 EIST enabled Coordination enabled
OOB Bit 8 reset OOB Bit 18 reset
3.) 0x1B1: IA32_PACKAGE_THERM_STATUS: 88410000
4.) 0x64F: MSR_CORE_PERF_LIMIT_REASONS: 0
A.) 0x1FC: MSR_POWER_CTL: 3C005D : C1E disable : EEO disable : RHO disable
5.) 0x771: IA32_HWP_CAPABILITIES (performance): 10B2930 : high 48 :
guaranteed 41 : efficient 11 : lowest 1
6.) 0x774: IA32_HWP_REQUEST:    CPU 0-11 :
    raw: 80003001 : 80003001 : 80003001 : 80003001 : 80003001 :
80003001 : 80003001 : 80003001 : 80003001 : 80003001 : 80003001 :
80003001 :
    min:        1 :        1 :        1 :        1 :        1 :
1 :        1 :        1 :        1 :        1 :        1 :        1 :
    max:       48 :       48 :       48 :       48 :       48 :
48 :       48 :       48 :       48 :       48 :       48 :       48 :
    des:        0 :        0 :        0 :        0 :        0 :
0 :        0 :        0 :        0 :        0 :        0 :        0 :
    epp:      128 :      128 :      128 :      128 :      128 :
128 :      128 :      128 :      128 :      128 :      128 :      128
:
    act:        0 :        0 :        0 :        0 :        0 :
0 :        0 :        0 :        0 :        0 :        0 :        0 :
7.) 0x777: IA32_HWP_STATUS: 0 : high 0 : guaranteed 0 : efficient 0 : lowest 0

...

... Doug