powernow-k7 does not work with 2.6.12 and SMP enabled

powernow-k7 does not work with 2.6.12 and SMP enabled

[Michael Prokop]

Hello,

(please CC me on replies as I'm not subscribed to the list, thanks.)

Compiling 2.6.12.3 with SMP-support *enabled* leads to a non-working
powernow-k7-module on my laptop using mobile AMD Duron(tm) ["Error
inserting powernow_k7 ... No such device"].

Disabling SMP-support results in a working module ["powernow:
Minimum speed 500 MHz. Maximum speed 1100 MHz."].

I do know that there are some issues with enabled SMP, but:
powernow-k7 works for me with 2.6.11 and *enabled* SMP.

Is there a specific reason why it does not work with 2.6.12 anymore?
Using the nosmp-kernelparameter (tell an SMP kernel to act as a UP
kernel) does not change the situation. Why does not the system
behave then like a kernel without SMP-support?

Relevant diff-output of dmesg booting once with a non-smp-kernel
(dmesg.2.6.12.3) and once with a smp-enabled kernel
(dmesg.2.6.12.3-smp):

      --- dmesg.2.6.12.3      2005-07-30 12:23:56.000000000 +0200
      +++ dmesg.2.6.12.3-smp  2005-07-30 12:27:01.000000000 +0200
      -Detected 1100.559 MHz processor.
      +Detected 1100.268 MHz processor.
      [...]
       Intel machine check architecture supported.
       Intel machine check reporting enabled on CPU#0.
      -CPU: AMD mobile AMD Duron(tm) stepping 02
       Enabling fast FPU save and restore... done.
       Enabling unmasked SIMD FPU exception support... done.
       Checking 'hlt' instruction... OK.
       ACPI: setting ELCR to 0200 (from 0620)
      +CPU0: AMD mobile AMD Duron(tm) stepping 02
      +SMP motherboard not detected.
      +Local APIC not detected. Using dummy APIC emulation.
      +Brought up 1 CPUs
      +CPU0 attaching sched-domain:
      + domain 0: span 0001
      +  groups: 0001
      +  domain 1: span 0001
      +   groups: 0001
       NET: Registered protocol family 16
      [...]
      [...]
       powernow: PowerNOW! Technology present. Can scale: frequency and voltage.
      -Detected 1100.387 MHz processor.
      -powernow: SGTC: 10000
      -powernow: Minimum speed 500 MHz. Maximum speed 1100 MHz.


Any chances that powernow(-k7) will work again with SMP-enabled
kernels? (I'd like to ship a smp-enabled kernel with my
linux-live-cd but use cpufreq anyway.)

More detailed information (dmesg-output, kernelconfig, cpuinfo) can
be found on http://grml.org/cpufreq/

I'd appreciate any feedback/help.

regards,
-mika-
-- 
 ,'"`.         http://www.michael-prokop.at/
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