RE: High-pitch noise with 2.6.0-test11

RE: High-pitch noise with 2.6.0-test11

[Grover, Andrew]

> [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of 
> Troels Walsted Hansen

> > itself (that wasn't there with 2.4). The noise happens only 
> when the CPU
> > is idle. Also, I have noticed that removing thermal.o makes 
> the noise
> > stop, which is very odd. Is there anything that can be done 
> about that?
> 
> I had the same problem with my Dell Latitude C600 and newer 
> kernels with 
>   HZ>100. The solution I found was to add "apm=idle-threshold=100" to 
> the kernel commandline, to disable APM idle calls.
> 
> You should monitor the temperature of your laptop to make sure it 
> doesn't spin wildly and create extra heat if you use the same 
> solution.
> 
> Using ACPI instead of APM might also be a solution?

Here's the answer from another thread:

"It's not normal, but it means they used cheap capacitors. This is known
as the acoustic noise issue. It's related to PCB vibration as a result
of the piezo electric effect on the caps. What is the timer tick
frequency? ... The 1ms gives a nice 1kHz tone. It's related to the
voltage change of C4 exit."

Regards -- Andy

RE: High-pitch noise with 2.6.0-test11

[Jean-Marc Valin]

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> Here's the answer from another thread:
> 
> "It's not normal, but it means they used cheap capacitors. This is known
> as the acoustic noise issue. It's related to PCB vibration as a result
> of the piezo electric effect on the caps. What is the timer tick
> frequency? ... The 1ms gives a nice 1kHz tone. It's related to the
> voltage change of C4 exit."

Well, that still doesn't explain why the noise is only there when I
insert thermal.o. Also, the noise seems to be higher than 1 kHz (I'd
guess 5-10 kHz).

	Jean-Marc

-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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High-pitch noise with 2.6.0-test11

[Jean-Marc Valin]

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Hi,

I just installed 2.6.0-test11 on my Dell Latitude D600 (Pentium-M)
laptop and I noticed a strange high-pitch noise comming from the laptop
itself (that wasn't there with 2.4). The noise happens only when the CPU
is idle. Also, I have noticed that removing thermal.o makes the noise
stop, which is very odd. Is there anything that can be done about that?

Another (unrelated) problem I noticed is the fact that since I upgraded
to 2.6, X started behaving strangely wrt left-click copy and
middle-click paste. Any idea what the cause can be? I'm using Fedora
Core 1.

Thanks,

	Jean-Marc

P.S. Please CC to me, since I'm not subscribed

-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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Re: High-pitch noise with 2.6.0-test11

[Jean-Marc Valin]

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> I just installed 2.6.0-test11 on my Dell Latitude D600 (Pentium-M)
> laptop and I noticed a strange high-pitch noise comming from the laptop
> itself (that wasn't there with 2.4). The noise happens only when the CPU
> is idle. Also, I have noticed that removing thermal.o makes the noise
> stop, which is very odd. Is there anything that can be done about that?

Actually, speaking of thermal.o, this is what I got when I tried to
remove it:

Unable to handle kernel paging request at virtual address f882e28f
 printing eip:
f882e28f
*pde = 37f86067
*pte = 00000000
Oops: 0000 [#1]
CPU:    0
EIP:    0060:[<f882e28f>]    Not tainted
EFLAGS: 00010296
EIP is at 0xf882e28f
eax: 00000000   ebx: 00091662   ecx: 00000008   edx: 00000000
esi: f79d12f8   edi: 000909e9   ebp: f79d1200   esp: c037bfc0
ds: 007b   es: 007b   ss: 0068
Process swapper (pid: 0, threadinfo=c037a000 task=c030d440)
Stack: 0009f600 00000000 c037a000 0009f600 c0105000 0008e000 c01090e4
00000816
       c037c74a c030d440 00000000 c03b2ec8 00000003 c037c470 c03b8100
c010017e
Call Trace:
 [<c0105000>] rest_init+0x0/0x60
 [<c01090e4>] cpu_idle+0x34/0x40
 [<c037c74a>] start_kernel+0x18a/0x1c0
 [<c037c470>] unknown_bootoption+0x0/0x120
                                                                                
Code:  Bad EIP value.
 <0>Kernel panic: Attempted to kill the idle task!
In idle task - not syncing

Hope this helps.

	Jean-Marc

P.S. I'm not subscribed to the list

-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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Re: High-pitch noise with 2.6.0-test11

[Troels Walsted Hansen]

Jean-Marc Valin wrote:
> I just installed 2.6.0-test11 on my Dell Latitude D600 (Pentium-M)
> laptop and I noticed a strange high-pitch noise comming from the laptop
> itself (that wasn't there with 2.4). The noise happens only when the CPU
> is idle. Also, I have noticed that removing thermal.o makes the noise
> stop, which is very odd. Is there anything that can be done about that?

I had the same problem with my Dell Latitude C600 and newer kernels with 
  HZ>100. The solution I found was to add "apm=idle-threshold=100" to 
the kernel commandline, to disable APM idle calls.

You should monitor the temperature of your laptop to make sure it 
doesn't spin wildly and create extra heat if you use the same solution.

Using ACPI instead of APM might also be a solution?

Troels

Re: High-pitch noise with 2.6.0-test11

[Jean-Marc Valin]

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Actually, I'm already using ACPI, so it's not an APM problem. I really
don't see what thermal.o can do to cause this.

	Jean-Marc

> I had the same problem with my Dell Latitude C600 and newer kernels with 
>   HZ>100. The solution I found was to add "apm=idle-threshold=100" to 
> the kernel commandline, to disable APM idle calls.
> 
> You should monitor the temperature of your laptop to make sure it 
> doesn't spin wildly and create extra heat if you use the same solution.
> 
> Using ACPI instead of APM might also be a solution?
> 
> Troels
-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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Re: High-pitch noise with 2.6.0-test11

[Andrew McGregor]

Nearly all Dell laptops do this, it's the power supply making that noise. 
The supply won't fail, but it's bad for the batteries.  The solution in 2.4 
was to turn off 'APM calls when CPU idle'.  I suspect unloading thermal.o 
has the same effect.

As for X, do you have the Synaptics touchpad X driver in Fedora core?  You 
probably need the kernel driver as well, and to check out the documentation 
(sorry, no pointer handy).  It's a bit different, in that the driver 
suppresses taps and clicks that are too close in time (by a configurable 
amount) to typing.  This avoids the common false mouse clicks caused by 
case flexure setting off the touchpad.  It also implements X events for 
corner taps, edge scroll regions, and pressure sense.  All in all, much 
better once understood, but it is different.

Andrew

--On Friday, 5 December 2003 1:31 a.m. -0500 Jean-Marc Valin 
<Jean-Marc.Valin@USherbrooke.ca> wrote:

> Hi,
>
> I just installed 2.6.0-test11 on my Dell Latitude D600 (Pentium-M)
> laptop and I noticed a strange high-pitch noise comming from the laptop
> itself (that wasn't there with 2.4). The noise happens only when the CPU
> is idle. Also, I have noticed that removing thermal.o makes the noise
> stop, which is very odd. Is there anything that can be done about that?
>
> Another (unrelated) problem I noticed is the fact that since I upgraded
> to 2.6, X started behaving strangely wrt left-click copy and
> middle-click paste. Any idea what the cause can be? I'm using Fedora
> Core 1.
>
> Thanks,
>
> 	Jean-Marc
>
> P.S. Please CC to me, since I'm not subscribed
>
> --
> Jean-Marc Valin, M.Sc.A., ing. jr.
> LABORIUS (http://www.gel.usherb.ca/laborius)
> Université de Sherbrooke, Québec, Canada



---------
Andrew McGregor
Director, Scientific Advisor
IndraNet Technologies Ltd
http://www.indranet-technologies.com/

Re: High-pitch noise with 2.6.0-test11

[Pavel Machek]

Hi!

> I just installed 2.6.0-test11 on my Dell Latitude D600 (Pentium-M)
> laptop and I noticed a strange high-pitch noise comming from the laptop
> itself (that wasn't there with 2.4). The noise happens only when the CPU
> is idle. Also, I have noticed that removing thermal.o makes the noise
> stop, which is very odd. Is there anything that can be done about that?

I'm afraid this is common prolem; most notebooks I sen do some kind of
annoying noise under some circumstances. Therewas technical discussion
about why that happens on ACPI list.
								Pavel
-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]

Re: High-pitch noise with 2.6.0-test11

[Jean-Marc Valin]

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> I'm afraid this is common prolem; most notebooks I sen do some kind of
> annoying noise under some circumstances. Therewas technical discussion
> about why that happens on ACPI list.

It seems like the noise frequency is directly related to the value of HZ
and HZ=1000 is especially annoying as the ear is very sensitive. I was
wondering how hard it would be to allow values of HZ in the range of
10-20 kHz? I have attempted to do so, but it seems like part of the code
is not ready for that. Even after setting the right SHIFT_HZ in timex.h,
setting HZ=10000 causes things like division by zero and negative
shifts. Is there a way to do it anyway?

        Jean-Marc

-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada

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