From: Fabio Comolli on
Hi.
I have an EeePC 900 running 2.6.34-rc1.

If I boot it on AC the cpu runs at full speed, 900MHz; if I boot it on
battery it runs only at 630Mhz. Plugging / unplugging the AC does not
change the cpu frequency. Only a reboot can change the situation.

I already tried to echo 0 or 1 to the
/sys/devices/platform/eeepc/cpufv file; no effects, even if the file
changes its value.

This is not a regression from 2.6.33: this behavior is also present in
that version.

Does this ring any bells? This is really annoying, especially when
trying to watch a movie on battery. Also 3D apps show a 30%
performance drop, as expected.

Regards,
Fabio
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From: Corentin Chary on
On Tue, Mar 9, 2010 at 11:58 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
> Hi.
> I have an EeePC 900 running 2.6.34-rc1.
>
> If I boot it on AC the cpu runs at full speed, 900MHz; if I boot it on
> battery it runs only at 630Mhz. Plugging / unplugging the AC does not
> change the cpu frequency. Only a reboot can change the situation.
>
> I already tried to echo 0 or 1 to the
> /sys/devices/platform/eeepc/cpufv file; no effects, even if the file
> changes its value.
>
> This is not a regression from 2.6.33: this behavior is also present in
> that version.
>
> Does this ring any bells? This is really annoying, especially when
> trying to watch a movie on battery. Also 3D apps show a 30%
> performance drop, as expected.

Can you change the frequency with cpufreq ?
Did you try all cpufv values (see cpufv_available file) ?
Is you bios up-to-date ?

--
Corentin Chary
http://xf.iksaif.net
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From: Fabio Comolli on
Hi.

On Wed, Mar 10, 2010 at 2:07 PM, Corentin Chary
<corentin.chary(a)gmail.com> wrote:
> On Tue, Mar 9, 2010 at 11:58 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
>> Hi.
>> I have an EeePC 900 running 2.6.34-rc1.
>>
>> If I boot it on AC the cpu runs at full speed, 900MHz; if I boot it on
>> battery it runs only at 630Mhz. Plugging / unplugging the AC does not
>> change the cpu frequency. Only a reboot can change the situation.
>>
>> I already tried to echo 0 or 1 to the
>> /sys/devices/platform/eeepc/cpufv file; no effects, even if the file
>> changes its value.
>>
>> This is not a regression from 2.6.33: this behavior is also present in
>> that version.
>>
>> Does this ring any bells? This is really annoying, especially when
>> trying to watch a movie on battery. Also 3D apps show a 30%
>> performance drop, as expected.
>
> Can you change the frequency with cpufreq ?

No, I can't. Which cpufreq driver am I supposed to use? With only
cpufreq compiled in, the directory
/sys/drivers/system/cpu/cpu0/cpufreq is empty.

> Did you try all cpufv values (see cpufv_available file) ?

Yes, it only shows 0 and 1. I tried both, without success.

> Is you bios up-to-date ?

Yes it is, it's 1006.

>
> --
> Corentin Chary
> http://xf.iksaif.net
>

Thanks.
Fabio
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From: Fabio Comolli on
HI again.

On Wed, Mar 10, 2010 at 2:46 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
> Hi.
>
> On Wed, Mar 10, 2010 at 2:07 PM, Corentin Chary
> <corentin.chary(a)gmail.com> wrote:
>> On Tue, Mar 9, 2010 at 11:58 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
>>> Hi.
>>> I have an EeePC 900 running 2.6.34-rc1.
>>>
>>> If I boot it on AC the cpu runs at full speed, 900MHz; if I boot it on
>>> battery it runs only at 630Mhz. Plugging / unplugging the AC does not
>>> change the cpu frequency. Only a reboot can change the situation.
>>>
>>> I already tried to echo 0 or 1 to the
>>> /sys/devices/platform/eeepc/cpufv file; no effects, even if the file
>>> changes its value.
>>>
>>> This is not a regression from 2.6.33: this behavior is also present in
>>> that version.
>>>
>>> Does this ring any bells? This is really annoying, especially when
>>> trying to watch a movie on battery. Also 3D apps show a 30%
>>> performance drop, as expected.
>>
>> Can you change the frequency with cpufreq ?
>
> No, I can't. Which cpufreq driver am I supposed to use? With only
> cpufreq compiled in, the directory
> /sys/drivers/system/cpu/cpu0/cpufreq is empty.

OK, there's something really wrong here.
I tried every possible cpufreq driver and the only one that loads is
p4-clockmod (the others say "no such device"). But...

The result is really unexpected, at least to me. The system switches
immediately to full speed, 900MHz (while running on battery). The
motivation is probably this:

[ 3.698307] conservative governor failed, too long transition
latency of HW, fallback to performance governor
[ 3.698334] p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available

The cause of this is probably that this driver thinks that my eeepc is
capable of many intermediate cpu frequency values:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
112500 225000 337500 450000 562500 675000 787500 900000

but the machine is only capable of 630 and 900MHz.

So, for me this is a really useful workaround: I compiled p4-clockmod
statically and so just a few seconds after boot I have my system
running at full speed :-)

To summarize:

-----Without p4-clockmod
* the eeepc-laptop cpufv interface doesn't work at all on my eeepc900
* this happens at least with 2.6.33 and 2.6.34-rc1
* if the system boots on AC power it stays forever at 900MHz
* if it boots on battery it stays forever at 630MHz

---With p4-clockmod
* the system boots at 630MHz if on battery
* as soon that p4-clockmod is loaded it switches to 900MHz
* p4-clockmod has a frequency table which is totally meaningless on the eeepc900

What a mess....

Regards,
Fabio

>
>> Did you try all cpufv values (see cpufv_available file) ?
>
> Yes, it only shows 0 and 1. I tried both, without success.
>
>> Is you bios up-to-date ?
>
> Yes it is, it's 1006.
>
>>
>> --
>> Corentin Chary
>> http://xf.iksaif.net
>>
>
> Thanks.
> Fabio
>
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From: Fabio Comolli on
Well, I'm sorry but I have some more detils to add.

On Wed, Mar 10, 2010 at 11:09 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
> HI again.
>
> On Wed, Mar 10, 2010 at 2:46 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
>> Hi.
>>
>> On Wed, Mar 10, 2010 at 2:07 PM, Corentin Chary
>> <corentin.chary(a)gmail.com> wrote:
>>> On Tue, Mar 9, 2010 at 11:58 PM, Fabio Comolli <fabio.comolli(a)gmail.com> wrote:
>>>> Hi.
>>>> I have an EeePC 900 running 2.6.34-rc1.
>>>>
>>>> If I boot it on AC the cpu runs at full speed, 900MHz; if I boot it on
>>>> battery it runs only at 630Mhz. Plugging / unplugging the AC does not
>>>> change the cpu frequency. Only a reboot can change the situation.
>>>>
>>>> I already tried to echo 0 or 1 to the
>>>> /sys/devices/platform/eeepc/cpufv file; no effects, even if the file
>>>> changes its value.
>>>>
>>>> This is not a regression from 2.6.33: this behavior is also present in
>>>> that version.
>>>>
>>>> Does this ring any bells? This is really annoying, especially when
>>>> trying to watch a movie on battery. Also 3D apps show a 30%
>>>> performance drop, as expected.
>>>
>>> Can you change the frequency with cpufreq ?
>>
>> No, I can't. Which cpufreq driver am I supposed to use? With only
>> cpufreq compiled in, the directory
>> /sys/drivers/system/cpu/cpu0/cpufreq is empty.
>
> OK, there's something really wrong here.
> I tried every possible cpufreq driver and the only one that loads is
> p4-clockmod (the others say "no such device"). But...
>
> The result is really unexpected, at least to me. The system switches
> immediately to full speed, 900MHz (while running on battery). The
> motivation is probably this:
>
> [    3.698307] conservative governor failed, too long transition
> latency of HW, fallback to performance governor
> [    3.698334] p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available
>
> The cause of this is probably that this driver thinks that my eeepc is
> capable of many intermediate cpu frequency values:
>
> cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
> 112500 225000 337500 450000 562500 675000 787500 900000
>
> but the machine is only capable of 630 and 900MHz.
>
> So, for me this is a really useful workaround: I compiled p4-clockmod
> statically and so just a few seconds after boot I have my system
> running at full speed :-)

Unfortunately this is not true. /proc/cpuinfo says:

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 13
model name : Intel(R) Celeron(R) M processor 900MHz
stepping : 8
cpu MHz : 900.000
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx up bts
bogomips : 1260.35
clflush size : 64
cache_alignment : 64
address sizes : 32 bits physical, 32 bits virtual

As you can see, 900MHz with only 1260.35 bogomips (the value
correspondent to 630MHz).

A quick performance test confirms that the cpu is running at 630MHz
and that the value reported by /proc/cpuinfo is totally fake.

>
> To summarize:
>
> -----Without p4-clockmod
> * the eeepc-laptop cpufv interface doesn't work at all on my eeepc900
> * this happens at least with 2.6.33 and 2.6.34-rc1
> * if the system boots on AC power it stays forever at 900MHz
> * if it boots on battery it stays forever at 630MHz
>
> ---With p4-clockmod
> * the system boots at 630MHz if on battery
> * as soon that p4-clockmod is loaded it switches to 900MHz
> * p4-clockmod has a frequency table which is totally meaningless on the eeepc900

* p4-clockmod does not work at all on the eeepc900 too!

>
> What a mess....
>

Indeed.

> Regards,
> Fabio
>

Fabio




>>
>>> Did you try all cpufv values (see cpufv_available file) ?
>>
>> Yes, it only shows 0 and 1. I tried both, without success.
>>
>>> Is you bios up-to-date ?
>>
>> Yes it is, it's 1006.
>>
>>>
>>> --
>>> Corentin Chary
>>> http://xf.iksaif.net
>>>
>>
>> Thanks.
>> Fabio
>>
>
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