RE: Sempron 2800+

RE: Sempron 2800+

[shin, jacob]

On Tuesday, September 12, 2006 11:03 AM Arik Raffael Funke wrote:

> dmesg | grep powern reports nothing at all... Is that supposed to be a
> good or bad thing? I fear for the latter. ;-)
> 
> Is there anything else I could provide to help with diagnosis?

It is very possible that your Sempron does not support frequency
scaling.  Easy way to check is with cpuid instruction.

Could you compile and run the following and copy us on the output?

Thanks,

Jacob Shin
AMD, Inc.

---

#include <stdio.h>

int main() {
	unsigned int my_edx;

	asm ("cpuid"
		: "=d"(my_edx)
		: "a"(0x80000007)
	);

	printf("%08x\n", my_edx);
	return 0;
}

Re: Sempron 2800+

[Arik Raffael Funke]

shin, jacob wrote:
 > On Tuesday, September 12, 2006 11:03 AM Arik Raffael Funke wrote:
 >
 >> dmesg | grep powern reports nothing at all... Is that supposed to be a
 >> good or bad thing? I fear for the latter. ;-)
 >>
 >> Is there anything else I could provide to help with diagnosis?
 >
 > It is very possible that your Sempron does not support frequency
 > scaling.  Easy way to check is with cpuid instruction.
 >
 > Could you compile and run the following and copy us on the output?

Hi Shin,
the code you provided gives:

[root@funke ~]# ./cputest
00000009
[root@funke ~]#

Regards,
Arik

Sempron 2800+

[Arik Raffael Funke]

Hello,

I am using kernel version 2.6.17.11 with built-in cpufreq support on a 
AMD Sempron 2800+. However, I do not have the directory 
/sys/devices/system/cpu/cpu0/cpufreq/

Can anybody tell me why? Does my cpu not support cpufreq or have i 
forgotten to select some kernel modules/configuration?

Cheers,
Arik

RE: Sempron 2800+

[Langsdorf, Mark]

> I am using kernel version 2.6.17.11 with built-in cpufreq 
> support on a AMD Sempron 2800+. However, I do not have the 
> directory /sys/devices/system/cpu/cpu0/cpufreq/
> 
> Can anybody tell me why? Does my cpu not support cpufreq or 
> have i forgotten to select some kernel modules/configuration?

What does `dmesg | grep powern` report?

I suspect that your Sempron doesn't have the bit enabled 
that tells the driver it supports PowerNow!.  Thus, the
driver doesn't load.  I haven't had a chance to determine
if there's a large batch of Sempron 2800s that don't
support PN!, or if they just use a different bit to 
indicate that support.

-Mark Langsdorf
AMD, Inc.

Re: Sempron 2800+

[Arik Raffael Funke]

Langsdorf, Mark wrote:
 >> I am using kernel version 2.6.17.11 with built-in cpufreq
 >> support on a AMD Sempron 2800+. However, I do not have the
 >> directory /sys/devices/system/cpu/cpu0/cpufreq/
 >>
 >> Can anybody tell me why? Does my cpu not support cpufreq or
 >> have i forgotten to select some kernel modules/configuration?
 >
 > What does `dmesg | grep powern` report?
 >
 > I suspect that your Sempron doesn't have the bit enabled
 > that tells the driver it supports PowerNow!.  Thus, the
 > driver doesn't load.  I haven't had a chance to determine
 > if there's a large batch of Sempron 2800s that don't
 > support PN!, or if they just use a different bit to
 > indicate that support.

dmesg | grep powern reports nothing at all... Is that supposed to be a 
good or bad thing? I fear for the latter. ;-)

Is there anything else I could provide to help with diagnosis?

Regards,
Arik