Li, Aubrey wrote:
>
> It looks like the BIOS only support native deep cstate method.
> We probably need to enable PDC.bit9.
>
> John, could you please help to verify it on your system?
>
> 1) reboot the system and enter kmdb
>
> 2) set a breakpoint at cpu_acpi_write_pdc()
> [0]> cpu_acpi_write_pdc:b
>
> 3) continue to hit the breakpoint
> [0]> :c
>
> 4) when the breakpoint is hit, change "cpupm_intel_pdccap" to 0xBBF.
> [0]> cpupm_intel_pdccap/W 0xBBF
>
> 5) continue to boot the system.
>
FWIW, on each of the eight i7 920 "cpus", 0xbbf replaced 0x9bf.
This experiment was more complex than anticipated. The first breakpoint
went fine. On the second breakpoint ([1]> ) no input was accepted
on the USB console keyboard. Switching this keyboard to the PS/2
input with a dongle fixed the problem.
After the system booted, powertop fails with:
powertop: ../common/cpufreq.c : cannot open dtrace library: DTrace
cannot be used when kernel debugger is active
but "kstat cstate" now produces output (it didn't before). If it matters,
the SBIOS option is still set to "Auto".
# kstat cstate
module: cstate instance: 1
name: c1 class: misc
address_space_id FFixedHW
crtime 201.053737219
latency 1
power 1000
snaptime 618.987573382
module: cstate instance: 1
name: c3 class: misc
address_space_id FFixedHW
crtime 201.053738694
latency 96
power 350
snaptime 618.987763894
module: cstate instance: 2
name: c1 class: misc
address_space_id FFixedHW
crtime 235.491583585
latency 1
power 1000
snaptime 618.987868627
module: cstate instance: 2
name: c3 class: misc
address_space_id FFixedHW
crtime 235.491585306
latency 96
power 350
snaptime 618.987962843
module: cstate instance: 3
name: c1 class: misc
address_space_id FFixedHW
crtime 254.080557069
latency 1
power 1000
snaptime 618.988062766
module: cstate instance: 3
name: c3 class: misc
address_space_id FFixedHW
crtime 254.080558851
latency 96
power 350
snaptime 618.988155771
module: cstate instance: 4
name: c1 class: misc
address_space_id FFixedHW
crtime 301.460281258
latency 1
power 1000
snaptime 618.98825552
module: cstate instance: 4
name: c3 class: misc
address_space_id FFixedHW
crtime 301.460282866
latency 96
power 350
snaptime 618.988349078
module: cstate instance: 5
name: c1 class: misc
address_space_id FFixedHW
crtime 354.306818526
latency 1
power 1000
snaptime 618.988449423
module: cstate instance: 5
name: c3 class: misc
address_space_id FFixedHW
crtime 354.306820203
latency 96
power 350
snaptime 618.988542142
module: cstate instance: 6
name: c1 class: misc
address_space_id FFixedHW
crtime 373.751687887
latency 1
power 1000
snaptime 618.988660284
module: cstate instance: 6
name: c3 class: misc
address_space_id FFixedHW
crtime 373.751690036
latency 96
power 350
snaptime 618.988753932
module: cstate instance: 7
name: c1 class: misc
address_space_id FFixedHW
crtime 388.831011112
latency 1
power 1000
snaptime 618.988854217
module: cstate instance: 7
name: c3 class: misc
address_space_id FFixedHW
crtime 388.831013099
latency 96
power 350
snaptime 618.988947075
#
