I recently upgraded from linux 2.4.27 to 2.6.8.1 and noticed my laptop
now makes a high pitch noise while idle. I traced it back to the
processor module for acpi. 'rmmod processor' stops the noise.
Using speed step to turn it down to 733 Mhz makes it a
little quieter and doesn't change the tone.
Is there any way to stop this? I googled around and found it had
something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
in the 2.4 kernel. I couldn't find much else on this. Hunting around the
code didn't help much, I don't know C.
The laptop is a Compaq Evo N160 from Dec 2001. The reference in google
was to a Centrino laptop with the same problem. I wrote to Dominik
Brodowski who suggested posting here.
fraz
Hi!
> I recently upgraded from linux 2.4.27 to 2.6.8.1 and noticed my laptop
> now makes a high pitch noise while idle. I traced it back to the
> processor module for acpi. 'rmmod processor' stops the noise.
>
>
>
> Using speed step to turn it down to 733 Mhz makes it a
> little quieter and doesn't change the tone.
>
>
>
> Is there any way to stop this? I googled around and found it had
> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> code didn't help much, I don't know C.
Change #define HZ 1000 to #define HZ 100...
Ouch and btw it is hardware problem -- too cheap capacitors.
Pavel
--
Boycott Kodak -- for their patent abuse against Java.
On Thursday 07 October 2004 11:30, Fraz wrote:
> I recently upgraded from linux 2.4.27 to 2.6.8.1 and noticed my laptop
> now makes a high pitch noise while idle. I traced it back to the
> processor module for acpi. 'rmmod processor' stops the noise.
>
> Using speed step to turn it down to 733 Mhz makes it a
> little quieter and doesn't change the tone.
>
> Is there any way to stop this? I googled around and found it had
> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> code didn't help much, I don't know C.
>
> The laptop is a Compaq Evo N160 from Dec 2001. The reference in google
> was to a Centrino laptop with the same problem. I wrote to Dominik
> Brodowski who suggested posting here.
Take a look at this bug report:
http://bugme.osdl.org/show_bug.cgi?id=2478
--
Christian Hesse
geek by nature
linux by choice
Pavel Machek <[email protected]> writes:
> Hi!
>
>> I recently upgraded from linux 2.4.27 to 2.6.8.1 and noticed my laptop
>> now makes a high pitch noise while idle. I traced it back to the
>> processor module for acpi. 'rmmod processor' stops the noise.
>>
>>
>>
>> Using speed step to turn it down to 733 Mhz makes it a
>> little quieter and doesn't change the tone.
>>
>>
>>
>> Is there any way to stop this? I googled around and found it had
>> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
>> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
>> code didn't help much, I don't know C.
>
> Change #define HZ 1000 to #define HZ 100...
... and lose all the benefits of HZ=1000. What would happen if one
were to set HZ to a higher value, like 10000?
> Ouch and btw it is hardware problem -- too cheap capacitors.
> Pavel
> --
> Boycott Kodak -- for their patent abuse against Java.
Actually, I don't know which is worse, patent abuse or Java misuse.
--
M?ns Rullg?rd
[email protected]
Hi!
> >> Is there any way to stop this? I googled around and found it had
> >> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> >> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> >> code didn't help much, I don't know C.
> >
> > Change #define HZ 1000 to #define HZ 100...
>
> ... and lose all the benefits of HZ=1000.
What benefits? HZ=1000 takes 1W more on my system.
> What would happen if one
> were to set HZ to a higher value, like 10000?
Try it.
> > Boycott Kodak -- for their patent abuse against Java.
>
> Actually, I don't know which is worse, patent abuse or Java misuse.
Well, java is ugly but not dangerous.
Pavel
--
64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
Hi!
> >> Is there any way to stop this? I googled around and found it had
> >> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> >> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> >> code didn't help much, I don't know C.
> >
> > Change #define HZ 1000 to #define HZ 100...
>
> ... and lose all the benefits of HZ=1000. What would happen if one
> were to set HZ to a higher value, like 10000?
You'll probably get even uglier noise and 5%+ performance penalty.
--
64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
Pavel Machek <[email protected]> writes:
> Hi!
>
>> >> Is there any way to stop this? I googled around and found it had
>> >> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
>> >> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
>> >> code didn't help much, I don't know C.
>> >
>> > Change #define HZ 1000 to #define HZ 100...
>>
>> ... and lose all the benefits of HZ=1000.
>
> What benefits? HZ=1000 takes 1W more on my system.
Isn't it supposed to give more accurate timing?
>> What would happen if one
>> were to set HZ to a higher value, like 10000?
>
> Try it.
>
>> > Boycott Kodak -- for their patent abuse against Java.
>>
>> Actually, I don't know which is worse, patent abuse or Java misuse.
>
> Well, java is ugly but not dangerous.
> Pavel
> --
> 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
Has that really happened?
--
M?ns Rullg?rd
[email protected]
On Thu, 2004-10-07 at 10:32, Pavel Machek wrote:
> Hi!
>
> > >> Is there any way to stop this? I googled around and found it had
> > >> something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> > >> in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> > >> code didn't help much, I don't know C.
> > >
> > > Change #define HZ 1000 to #define HZ 100...
> >
> > ... and lose all the benefits of HZ=1000.
>
> What benefits? HZ=1000 takes 1W more on my system.
>
Better timer resolution?
Lee
Hi!
> >> >> code didn't help much, I don't know C.
> >> >
> >> > Change #define HZ 1000 to #define HZ 100...
> >>
> >> ... and lose all the benefits of HZ=1000.
> >
> > What benefits? HZ=1000 takes 1W more on my system.
>
> Isn't it supposed to give more accurate timing?
Well, yes, but if it beeps for you... Accurate timing is probably not
that important.
> > 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
>
> Has that really happened?
Yes. On gprs it is rather easy to reproduce, unfortunately...
Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
On Sad, 2004-10-16 at 20:52, Lee Revell wrote:
> > What benefits? HZ=1000 takes 1W more on my system.
> Better timer resolution?
And heavily reduced accuracy on a lot of laptops where 1000Hz
is enough to make the clock slide every time the battery state is
queried or an SMM event triggers.
Getting the best of both worlds depends on the stuff discussed at OLS
being finished, then you can have 1Khz accurancy and battery life
On Thu, 7 Oct 2004 12:32:10 +0200, Pavel Machek <[email protected]> wrote:
> > Is there any way to stop this? I googled around and found it had
> > something to do with idle frequency of 1000 Hz in 2.6 instead of 100Hz
> > in the 2.4 kernel. I couldn't find much else on this. Hunting around the
> > code didn't help much, I don't know C.
>
> Change #define HZ 1000 to #define HZ 100...
Helped an Asus S1300N. Not sure it's gone completely, but it's more
comfortable now.
To the original poster: look in include/asm/param.h
On Sat, 2004-10-16 at 17:46, Alan Cox wrote:
> On Sad, 2004-10-16 at 20:52, Lee Revell wrote:
> > > What benefits? HZ=1000 takes 1W more on my system.
> > Better timer resolution?
>
> And heavily reduced accuracy on a lot of laptops where 1000Hz
> is enough to make the clock slide every time the battery state is
> queried or an SMM event triggers.
>
Wouldn't such a laptop be horribly broken? 1ms is a LONG time to
disable interrupts. That's millions of CPU cycles...
> Getting the best of both worlds depends on the stuff discussed at OLS
> being finished, then you can have 1Khz accurancy and battery life
>
I was not there but I imagine this involves a way to get 1khz accuracy
with a 100Hz timer interrupt rate?
Lee
On Oct 16, 2004, at 21:24, Lee Revell wrote:
> I was not there but I imagine this involves a way to get 1khz accuracy
> with a 100Hz timer interrupt rate?
I think the idea is to (depending on the hardware) dynamically adjust
the
system timers to exactly the time necessary. If you don't have any
important
processes that will interrupt within the next 10ms then you can just go
ahead and set the timer longer. If properly done you might even be able
to set HZ to 20 or 50. Hardware interrupts would trigger immediate
responses, but otherwise a non-interactive system could minimize the
number of context switches and make the processor cache that much
more useful. This would still be bad on an interactive/desktop system
because it would mean that perceptive users could detect the switching
if they have two computationally intensive jobs running simultaneously.
Cheers,
Kyle Moffett
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCM/CS/IT/U d- s++: a17 C++++>$ UB/L/X/*++++(+)>$ P+++(++++)>$
L++++(+++) E W++(+) N+++(++) o? K? w--- O? M++ V? PS+() PE+(-) Y+
PGP+++ t+(+++) 5 X R? tv-(--) b++++(++) DI+ D+ G e->++++$ h!*()>++$ r
!y?(-)
------END GEEK CODE BLOCK------
On Sul, 2004-10-17 at 02:24, Lee Revell wrote:
> > And heavily reduced accuracy on a lot of laptops where 1000Hz
> > is enough to make the clock slide every time the battery state is
> > queried or an SMM event triggers.
> Wouldn't such a laptop be horribly broken? 1ms is a LONG time to
> disable interrupts. That's millions of CPU cycles...
Yes, and most laptops have this problem. They use SMM traps to talk to
the battery including huge delay loops and during those SMM traps no
interrupt code runs.
> > Getting the best of both worlds depends on the stuff discussed at OLS
> > being finished, then you can have 1Khz accurancy and battery life
> I was not there but I imagine this involves a way to get 1khz accuracy
> with a 100Hz timer interrupt rate?
Think about
add_timeout(timer, when, precision_desired)
On Sat, 2004-10-16 at 22:21, Alan Cox wrote:
> On Sul, 2004-10-17 at 02:24, Lee Revell wrote:
> > > And heavily reduced accuracy on a lot of laptops where 1000Hz
> > > is enough to make the clock slide every time the battery state is
> > > queried or an SMM event triggers.
> > Wouldn't such a laptop be horribly broken? 1ms is a LONG time to
> > disable interrupts. That's millions of CPU cycles...
>
> Yes, and most laptops have this problem. They use SMM traps to talk to
> the battery including huge delay loops and during those SMM traps no
> interrupt code runs.
>
Ugh! I was under the impression that mostly older machines had this
problem and it was a minority of laptops. I could not find a lot of
info on SMM - several of the links I found were DDJ "Undocumented
Corner" articles.
Anyway this explains probably half the weird bug reports on the linux
audio user list.
Lee
Alan Cox writes:
> On Sad, 2004-10-16 at 20:52, Lee Revell wrote:
>> [Pavel Machek]
>>> What benefits? HZ=1000 takes 1W more on my system.
>>
>> Better timer resolution?
>
> And heavily reduced accuracy on a lot of laptops
> where 1000Hz is enough to make the clock slide
> every time the battery state is queried or an SMM
> event triggers.
How low is low enough for nearly all of these laptops?
Some decent choices:
wrongness_% HZ_diff PIT_# HZ actual_HZ
-0.00083809 -0.003051 3278 364 363.996949
-0.00016762 -0.000483 4143 288 287.999517
-0.00016762 -0.000724 2762 432 431.999276
-0.00016762 -0.001448 1381 864 863.998552
+0.00008381 +0.000304 3287 363 363.000304
+0.00008381 +0.000435 2299 519 519.000435
+0.00008381 +0.000525 1903 627 627.000525
>Hi!
>
>> >> Is there any way to stop this? I googled around and found it had
>> >> something to do with idle frequency of 1000 Hz in 2.6
>instead of 100Hz
>> >> in the 2.4 kernel. I couldn't find much else on this.
>Hunting around the
>> >> code didn't help much, I don't know C.
>> >
>> > Change #define HZ 1000 to #define HZ 100...
>>
>> ... and lose all the benefits of HZ=1000. What would happen if one
>> were to set HZ to a higher value, like 10000?
There is a similar issue filed on :
http://bugzilla.kernel.org/show_bug.cgi?id=3406
Hi!
> >> ... and lose all the benefits of HZ=1000. What would happen if one
> >> were to set HZ to a higher value, like 10000?
>
> There is a similar issue filed on :
> http://bugzilla.kernel.org/show_bug.cgi?id=3406
>
He he, someone should write a driver to play music on
those capacitors....
Pavel
--
64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
Pavel Machek <[email protected]> writes:
> Hi!
>
>> >> >> ... and lose all the benefits of HZ=1000. What would happen if one
>> >> >> were to set HZ to a higher value, like 10000?
>> >>
>> >> There is a similar issue filed on :
>> >> http://bugzilla.kernel.org/show_bug.cgi?id=3406
>> >>
>> >
>> > He he, someone should write a driver to play music on
>> > those capacitors....
>>
>> Why not? They used to have special files that played music on the
>> printer when printed.
>
> Yes, it would be nice... to scare people :-). Also with such piece of
> software it would be rather easy to tell if given mainboard is junk.
I've noticed my laptop makes a slight noise whenever there's heavy
network traffic. Maybe that could be used to control the pitch even
without a kernel hack.
--
M?ns Rullg?rd
[email protected]
On Wed, 2004-10-20 at 12:37, M?ns Rullg?rd wrote:
> I've noticed my laptop makes a slight noise whenever there's heavy
> network traffic. Maybe that could be used to control the pitch even
> without a kernel hack.
Well, in your case the bad capacitors might be in the NIC. The ethernet
phones at my last job were so cheaply made that you could hear it ARPing
through your computer speakers.
I bet you could actually identify the singing capacitor using a
telephone toner wand. IMHO this is a bad enough problem to RMA it.
What if you had bought the thing for sound recording?
Lee
Hi!
> > >> > He he, someone should write a driver to play music on
> > >> > those capacitors....
> > >> Why not? They used to have special files that played music on the
> > >> printer when printed.
> > > Yes, it would be nice... to scare people :-). Also with such piece of
> > > software it would be rather easy to tell if given mainboard is junk.
> > I've noticed my laptop makes a slight noise whenever there's heavy
> > network traffic. Maybe that could be used to control the pitch even
> > without a kernel hack.
>
> That would make up a pure userspace driver, even for a remotely
> accessibly hardware device. Cool:-)
"Help! Not only are our machines under Distributed DoS attack, they
also play Yankee Doodle ;-)))."
Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
On Wed, 2004-10-20 18:37:42 +0200, M?ns Rullg?rd <[email protected]>
wrote in message <[email protected]>:
> Pavel Machek <[email protected]> writes:
> >> > He he, someone should write a driver to play music on
> >> > those capacitors....
> >> Why not? They used to have special files that played music on the
> >> printer when printed.
> > Yes, it would be nice... to scare people :-). Also with such piece of
> > software it would be rather easy to tell if given mainboard is junk.
> I've noticed my laptop makes a slight noise whenever there's heavy
> network traffic. Maybe that could be used to control the pitch even
> without a kernel hack.
That would make up a pure userspace driver, even for a remotely
accessibly hardware device. Cool:-)
MfG, JBG
--
Jan-Benedict Glaw [email protected] . +49-172-7608481 _ O _
"Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg _ _ O
fuer einen Freien Staat voll Freier B?rger" | im Internet! | im Irak! O O O
ret = do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA));
Pavel Machek wrote:
> Hi!
>
> > >> ... and lose all the benefits of HZ=1000. What would happen if one
> > >> were to set HZ to a higher value, like 10000?
> >
> > There is a similar issue filed on :
> > http://bugzilla.kernel.org/show_bug.cgi?id=3406
> >
>
> He he, someone should write a driver to play music on
> those capacitors....
A new ALSA driver? :)
--
Giuseppe "Oblomov" Bilotta
Can't you see
It all makes perfect sense
Expressed in dollar and cents
Pounds shillings and pence
(Roger Waters)
Lee Revell <[email protected]> writes:
> On Wed, 2004-10-20 at 12:37, M?ns Rullg?rd wrote:
>> I've noticed my laptop makes a slight noise whenever there's heavy
>> network traffic. Maybe that could be used to control the pitch even
>> without a kernel hack.
>
> Well, in your case the bad capacitors might be in the NIC. The ethernet
> phones at my last job were so cheaply made that you could hear it ARPing
> through your computer speakers.
I have and old Alphastation where the onboard sound card picks up all
sorts of noise. If you connect some speakers everything gets it's own
special noise, from cache misses to SCSI traffic.
> I bet you could actually identify the singing capacitor using a
> telephone toner wand. IMHO this is a bad enough problem to RMA it.
Not really, it's barely noticeable in a quiet room.
--
M?ns Rullg?rd
[email protected]
Hi!
> >> >> ... and lose all the benefits of HZ=1000. What would happen if one
> >> >> were to set HZ to a higher value, like 10000?
> >>
> >> There is a similar issue filed on :
> >> http://bugzilla.kernel.org/show_bug.cgi?id=3406
> >>
> >
> > He he, someone should write a driver to play music on
> > those capacitors....
>
> Why not? They used to have special files that played music on the
> printer when printed.
Yes, it would be nice... to scare people :-). Also with such piece of
software it would be rather easy to tell if given mainboard is junk.
Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
Pavel Machek <[email protected]> writes:
> Hi!
>
>> >> ... and lose all the benefits of HZ=1000. What would happen if one
>> >> were to set HZ to a higher value, like 10000?
>>
>> There is a similar issue filed on :
>> http://bugzilla.kernel.org/show_bug.cgi?id=3406
>>
>
> He he, someone should write a driver to play music on
> those capacitors....
Why not? They used to have special files that played music on the
printer when printed.
--
M?ns Rullg?rd
[email protected]
On Wed, 2004-10-20 at 13:13, M?ns Rullg?rd wrote:
> > I bet you could actually identify the singing capacitor using a
> > telephone toner wand. IMHO this is a bad enough problem to RMA it.
>
> Not really, it's barely noticeable in a quiet room.
If you had bought that laptop for audio use (big market these days, just
look at all the FireWire/USB/PCMCIA sound hardware out there), then this
would be a fatal problem.
Of course, for such a user, a BIOS where the hardware constantly block
interrupts via SMM would also be a fatal problem because it ruins audio
latency. According to Alan Cox this is most laptops these days!
I am beginning to suspect the only known good laptop for pro audio use
is a Powerbook :-/. x86 laptops are just too cheaply made.
Lee
On Thu, 21 Oct 2004 16:32:08 -0400, Lee Revell <[email protected]> wrote:
> I am beginning to suspect the only known good laptop for pro audio use
> is a Powerbook :-/. x86 laptops are just too cheaply made.
Google suggests the Powerbook has also seen issues with singing
capacitors but I have to say that I have not experienced this with
mine - who wants an Intel POS laptop anyway ;-)
Jon.
On Oct 16, 2004, Alan Cox <[email protected]> wrote:
> Yes, and most laptops have this problem. They use SMM traps to talk to
> the battery
Hmm... Since the SMM on this AMD64 notebook we've been talking about
on the thread about USB handoff isn't exactly AMD64-compliant, could
this be the reason why I can't get battery information? I'm yet to
install a 32-bit-only system on this box to see whether it makes any
difference.
--
Alexandre Oliva http://www.ic.unicamp.br/~oliva/
Red Hat Compiler Engineer aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist oliva@{lsd.ic.unicamp.br, gnu.org}