[lm-sensors] reset=1 required for PWM control on Asus P4P800 Deluxe

[lm-sensors] reset=1 required for PWM control on Asus P4P800 Deluxe

[Stephen Kitt]

Hi,

I've been using fancontrol for a while to control my CPU fan. I'm using an
Asus P4P800 Deluxe board with a W83627THF controller which has PWM2 wired to
control the CPU fan (there are two other headers on the board, but they only
report the fan speed, their PWM isn't connected).

I switched to 2.6.14 yesterday and noticed today that the CPU fan was stuck
at the speed the BIOS cruise control left it at before the w83627hf module
was loaded. Changing the PWM value via /sys/bus/i2c/devices/.../pwm2 had no
effect. Loading the module with reset=1 fixed things, and I noticed in my
logs the request to report its usefulness. I compared the code from 2.6.13 to
2.6.14 and saw the change (and the comment!).

So here's a reason why it's needed ;-)

I hope this is useful; if you need more info, please cc me, I'm not
subscribed to the list.

Regards,

Stephen Kitt

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Jean Delvare]

Hi Stephen,

On 2005-11-06, Stephen Kitt wrote:
> I've been using fancontrol for a while to control my CPU fan. I'm using
> an Asus P4P800 Deluxe board with a W83627THF controller which has PWM2
> wired to control the CPU fan (there are two other headers on the board,
> but they only report the fan speed, their PWM isn't connected).
>
> I switched to 2.6.14 yesterday and noticed today that the CPU fan was
> stuck at the speed the BIOS cruise control left it at before the
> w83627hf module was loaded.

I'm a bit surprised by this statement. Cruise control (or Q-fan, as Asus
calls it) supposedly means that the chip dynamically changes the CPU fan
speed depending to the CPU temperature. So the CPU fan shouldn't be
"stuck" as you wrote. It should increase with CPU load. Isn't it the
case?

> Changing the PWM value via /sys/bus/i2c/devices/.../pwm2 had no
> effect. Loading the module with reset=1 fixed things, and I noticed
> in my logs the request to report its usefulness. I compared the code
> from 2.6.13 to 2.6.14 and saw the change (and the comment!).

Thanks a lot for reporting, so that we can go on improving the driver.

> So here's a reason why it's needed ;-)
>
> I hope this is useful; if you need more info (...)

Yes, I'd like you to do some tests.

First, here is what I think is happening. Your BIOS sets the W83627THF
chip in "thermal cruise" mode, where the fan speed is adjusted
depending on CPU temperature. The driver used to reset to the default
settings, thus voiding the BIOS configuration. In the default mode, the
fan speed can be manually controlled using /sys/.../pwm2. However, in
"thermal cruise" mode, you can't, as the speed is automatically
regulated. As the new driver leaves the chip in the mode the BIOS set it
in (unless you use reset=1), manual control is disabled.

I agree that the current situation is inconsistent. When the chip is
found in automatic fan control mode, we should either not present the
pwm files, or provide a way to revert to manual control mode.

But actually there is a patch floating around which adds full support for
the automatic modes of the W83627THF to the w83627hf driver. It wasn't
merged yet because it doesn't follow the standard interface, and would
need to be reviewed. But merging it would solve the issue.

Eric, you were supposed to resend the latest version of the patch on the
sensors-list, but I can't actually find it in the archives. Can you
please send it now, either as a text/plain or text/x-patch attachement,
or inline if you are certain your mailer will not wrap it badly? We need
to start from the latest version of the patch.

One thing I know for sure is that we will have to get rid of all the
"qfan" names. "Q-fan" is a name from Asus. It might even be (R) or
(TM) by them. The driver is for a Winbond chip, so we better use Winbond
names, or generic names.

Stephen, do you have some kernel programming knowledge? We need someone
to put the patch in conformance with the standard sysfs interface before
we can integrate it. If not, can you at least test patches against
recent kernels?

Stephen, can you please do the following tests:

1* In the BIOS setup screen, disable Q-fan, then boot Linux 2.6.14. You
should not need the reset=1 parameter, pwm2 should work out of the box,
because the BIOS will have left the chip in default configuration.

2* In the BIOS setup screen, enable Q-fan, and set the "fan speed
ratio" to, say, 13/16. Then boot Linux and report the output of
"isadump 0x295 0x296". Try again with a different value, say 11/16,
and report the output of the same dump. I want to know what register it
affects. I'd guess 0x09, but a confirmation would be welcome.

Thanks,
--
Jean Delvare

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Stephen Kitt]

On Mon, 7 Nov 2005 13:02:06 +0100 (CET), "Jean Delvare" <khali@linux-fr.org>
wrote:
> On 2005-11-06, Stephen Kitt wrote:
> > I switched to 2.6.14 yesterday and noticed today that the CPU fan was
> > stuck at the speed the BIOS cruise control left it at before the
> > w83627hf module was loaded.
> 
> I'm a bit surprised by this statement. Cruise control (or Q-fan, as Asus
> calls it) supposedly means that the chip dynamically changes the CPU fan
> speed depending to the CPU temperature. So the CPU fan shouldn't be
> "stuck" as you wrote. It should increase with CPU load. Isn't it the
> case?

Well, the fan slows down during the BIOS POST, but it never budges once Linux
has loaded - that's how I noticed the change. By "stuck" I meant that writing
to the pwm2 control file didn't change the fan speed. The fan's speed didn't
change with the CPU temperature either, but that might not mean much. I'm
running a 2.6GHz P4C with a Zalman CNPS7000-AlCu cooler, so the CPU stays
reasonably cool even under load. The fan's maximum speed is 2600rpm; with
Q-Fan at 11/16 it runs at 2100rpm. I tried loading the CPU as much as
possible this evening after a reboot, but I couldn't get it much beyond 50?C -
so if the BIOS's settings are anything like those the W83627THF's spec sheet
mentions (a target temperature of 55?C +/- 3?C), the fan speed wouldn't be
expected to change. I'd assume Q-Fan is behaving the way it's supposed to
given the Winbond documentation - I'd got used to fancontrol which behaves
rather differently on my system!

> Yes, I'd like you to do some tests.
> 
> First, here is what I think is happening. Your BIOS sets the W83627THF
> chip in "thermal cruise" mode, where the fan speed is adjusted
> depending on CPU temperature. The driver used to reset to the default
> settings, thus voiding the BIOS configuration. In the default mode, the
> fan speed can be manually controlled using /sys/.../pwm2. However, in
> "thermal cruise" mode, you can't, as the speed is automatically
> regulated. As the new driver leaves the chip in the mode the BIOS set it
> in (unless you use reset=1), manual control is disabled.

Indeed, this seems to be the case - as I mentioned above, my testing doesn't
prove or disprove anything with regards to the expected Q-Fan behaviour.

[...]

> One thing I know for sure is that we will have to get rid of all the
> "qfan" names. "Q-fan" is a name from Asus. It might even be (R) or
> (TM) by them. The driver is for a Winbond chip, so we better use Winbond
> names, or generic names.

The Winbond documentation mentions "SpeedFan(TM) Control" and "Thermal
Cruise", as you mention. I'd mixed the two up ;-)

> Stephen, do you have some kernel programming knowledge? We need someone
> to put the patch in conformance with the standard sysfs interface before
> we can integrate it. If not, can you at least test patches against
> recent kernels?

I'm afraid I don't have any kernel-specific programming knowledge - certainly
not enough to make the patch conform to the standard sysfs interface, of
which I know nothing! I'd be happy to test patches against recent kernels
though.

> Stephen, can you please do the following tests:
> 
> 1* In the BIOS setup screen, disable Q-fan, then boot Linux 2.6.14. You
> should not need the reset=1 parameter, pwm2 should work out of the box,
> because the BIOS will have left the chip in default configuration.

Yup, disabling Q-Fan allows fancontrol to control the fan without my having
to specify reset=1 when loading the w83627hf module.

> 2* In the BIOS setup screen, enable Q-fan, and set the "fan speed
> ratio" to, say, 13/16. Then boot Linux and report the output of
> "isadump 0x295 0x296". Try again with a different value, say 11/16,
> and report the output of the same dump. I want to know what register it
> affects. I'd guess 0x09, but a confirmation would be welcome.

I'm attaching three files: qfnone.txt is the register dump with Q-Fan
disabled, qf1116.txt with Q-Fan enabled at 11/16 (2100rpm or thereabouts),
and qf1316.txt with Q-Fan enabled at 13/16 (2350rpm or thereabouts). You're
right, register 0x09 changes, but others do too - some with the same values
as 0x09, some with another pair of values (eg. register 0x29).

Regards,

Stephen
-------------- next part --------------
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00: 01 ff 01 b1 10 00 37 30 01 b1 01 b1 3c 3c 05 03 
10: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
20: 65 cb d7 be ff 00 00 23 72 50 70 00 00 d9 b2 d9 
30: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
40: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
50: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
60: 65 cb d7 be ff 00 00 23 72 50 70 00 00 d9 b2 d9 
70: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
80: 01 ff 01 b1 10 00 37 30 01 b1 01 b1 3c 3c 05 03 
90: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
a0: 65 cb d7 be ff 00 00 23 72 50 70 00 00 d9 b2 d9 
b0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
c0: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
d0: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
e0: 65 cb d7 be ff 00 00 23 72 50 70 00 00 d9 b2 d9 
f0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
-------------- next part --------------
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00: 01 ff 01 d1 10 00 37 30 01 d1 01 d1 3c 3c 05 03 
10: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
20: 65 cb d7 be ff 00 00 23 72 47 70 00 00 d9 b2 d9 
30: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
40: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
50: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
60: 65 cb d7 be ff 00 00 23 72 47 70 00 00 d9 b2 d9 
70: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
80: 01 ff 01 d1 10 00 37 30 01 d1 01 d1 3c 3c 05 03 
90: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
a0: 65 cb d7 be ff 00 00 23 72 47 70 00 00 d9 b2 d9 
b0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
c0: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
d0: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
e0: 65 cb d7 be ff 00 00 23 72 47 70 00 00 d9 b2 d9 
f0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
-------------- next part --------------
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00: 01 ff 01 ff 00 00 37 30 01 b1 01 b1 3c 3c 05 03 
10: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
20: 65 ca d7 bf ff 00 00 22 72 41 70 00 00 d9 b2 d9 
30: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
40: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
50: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
60: 65 ca d7 bf ff 00 00 22 72 41 70 00 00 d9 b2 d9 
70: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
80: 01 ff 01 ff 00 00 37 30 01 b1 01 b1 3c 3c 05 03 
90: 01 ff 10 00 00 01 01 3c 42 00 ff ff 24 32 00 de 
a0: 65 ca d7 bf ff 00 00 22 72 41 70 00 00 d9 b2 d9 
b0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 
c0: 03 00 00 fe ff 00 00 ff 1f 03 89 c4 58 95 00 a3 
d0: ff ff 80 ff ff ff 00 00 90 20 ff ff 11 04 ff 05 
e0: 65 ca d7 bf ff 00 00 22 72 41 70 00 00 d9 b2 d9 
f0: c4 c5 b2 15 32 00 08 08 00 2d 28 fe fe fe 00 00 

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Jacques Facquet]

Le Dimanche 6 Novembre 2005 22:44, Stephen Kitt a ?crit :

> I switched to 2.6.14 yesterday and noticed today that the CPU fan
> was stuck at the speed the BIOS cruise control left it at before
> the w83627hf module was loaded. Changing the PWM value via
> /sys/bus/i2c/devices/.../pwm2 had no effect. Loading the module
> with reset=1 fixed things, and I noticed in my logs the request to
> report its usefulness. I compared the code from 2.6.13 to 2.6.14
> and saw the change (and the comment!).
This solved my problem too.
dmesg
Trying to free nonexistent resource <00000290-00000297>
(after reloading the driver)

w83627hf 9191-0290: If reset=1 solved a problem you were having, 
please report!

Soltek QBic EQ-3401A-V2

request_region(address, WINB_EXTENT, w83627hf_driver.name) return an 
error, without checking this error, the driver load but I have an 
error in unloading it.


-- 
Jacques Facquet.

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Eric Pascal]

	I have been submitting a patch to enable Fan speed control on my P4P800, and if you disable Q-Fan in the BIOS it work perfectly, you just set the temperature you want, the tolerance and the step and it works perfectly, don't need to rely on any tool like Speedfan on Windows to set the speed of my fan. The patch is being tested and modified to comply with lm-sensors standard. But if you are interested I can send you the patch that works great.

-----Message d'origine-----
De : Stephen Kitt [mailto:lists@sk2.org]
Envoy? : lundi 7 novembre 2005 22:11
? : Jean Delvare
Cc : LM Sensors; Eric Pascal
Objet : Re: [lm-sensors] reset=1 required for PWM control on Asus P4P800
Deluxe


On Mon, 7 Nov 2005 13:02:06 +0100 (CET), "Jean Delvare" <khali@linux-fr.org>
wrote:
> On 2005-11-06, Stephen Kitt wrote:
> > I switched to 2.6.14 yesterday and noticed today that the CPU fan was
> > stuck at the speed the BIOS cruise control left it at before the
> > w83627hf module was loaded.
> 
> I'm a bit surprised by this statement. Cruise control (or Q-fan, as Asus
> calls it) supposedly means that the chip dynamically changes the CPU fan
> speed depending to the CPU temperature. So the CPU fan shouldn't be
> "stuck" as you wrote. It should increase with CPU load. Isn't it the
> case?

Well, the fan slows down during the BIOS POST, but it never budges once Linux
has loaded - that's how I noticed the change. By "stuck" I meant that writing
to the pwm2 control file didn't change the fan speed. The fan's speed didn't
change with the CPU temperature either, but that might not mean much. I'm
running a 2.6GHz P4C with a Zalman CNPS7000-AlCu cooler, so the CPU stays
reasonably cool even under load. The fan's maximum speed is 2600rpm; with
Q-Fan at 11/16 it runs at 2100rpm. I tried loading the CPU as much as
possible this evening after a reboot, but I couldn't get it much beyond 50?C -
so if the BIOS's settings are anything like those the W83627THF's spec sheet
mentions (a target temperature of 55?C +/- 3?C), the fan speed wouldn't be
expected to change. I'd assume Q-Fan is behaving the way it's supposed to
given the Winbond documentation - I'd got used to fancontrol which behaves
rather differently on my system!

> Yes, I'd like you to do some tests.
> 
> First, here is what I think is happening. Your BIOS sets the W83627THF
> chip in "thermal cruise" mode, where the fan speed is adjusted
> depending on CPU temperature. The driver used to reset to the default
> settings, thus voiding the BIOS configuration. In the default mode, the
> fan speed can be manually controlled using /sys/.../pwm2. However, in
> "thermal cruise" mode, you can't, as the speed is automatically
> regulated. As the new driver leaves the chip in the mode the BIOS set it
> in (unless you use reset=1), manual control is disabled.

Indeed, this seems to be the case - as I mentioned above, my testing doesn't
prove or disprove anything with regards to the expected Q-Fan behaviour.

[...]

> One thing I know for sure is that we will have to get rid of all the
> "qfan" names. "Q-fan" is a name from Asus. It might even be (R) or
> (TM) by them. The driver is for a Winbond chip, so we better use Winbond
> names, or generic names.

The Winbond documentation mentions "SpeedFan(TM) Control" and "Thermal
Cruise", as you mention. I'd mixed the two up ;-)

> Stephen, do you have some kernel programming knowledge? We need someone
> to put the patch in conformance with the standard sysfs interface before
> we can integrate it. If not, can you at least test patches against
> recent kernels?

I'm afraid I don't have any kernel-specific programming knowledge - certainly
not enough to make the patch conform to the standard sysfs interface, of
which I know nothing! I'd be happy to test patches against recent kernels
though.

> Stephen, can you please do the following tests:
> 
> 1* In the BIOS setup screen, disable Q-fan, then boot Linux 2.6.14. You
> should not need the reset=1 parameter, pwm2 should work out of the box,
> because the BIOS will have left the chip in default configuration.

Yup, disabling Q-Fan allows fancontrol to control the fan without my having
to specify reset=1 when loading the w83627hf module.

> 2* In the BIOS setup screen, enable Q-fan, and set the "fan speed
> ratio" to, say, 13/16. Then boot Linux and report the output of
> "isadump 0x295 0x296". Try again with a different value, say 11/16,
> and report the output of the same dump. I want to know what register it
> affects. I'd guess 0x09, but a confirmation would be welcome.

I'm attaching three files: qfnone.txt is the register dump with Q-Fan
disabled, qf1116.txt with Q-Fan enabled at 11/16 (2100rpm or thereabouts),
and qf1316.txt with Q-Fan enabled at 13/16 (2350rpm or thereabouts). You're
right, register 0x09 changes, but others do too - some with the same values
as 0x09, some with another pair of values (eg. register 0x29).

Regards,

Stephen

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Jean Delvare]

Hi Jacques,

On 2005-11-08, Jacques Facquet wrote:
> This solved my problem too.
> dmesg
> Trying to free nonexistent resource <00000290-00000297>
> (after reloading the driver)
>
> w83627hf 9191-0290: If reset=1 solved a problem you were having,
> please report!
>
> Soltek QBic EQ-3401A-V2
>
> request_region(address, WINB_EXTENT, w83627hf_driver.name) return an
> error, without checking this error, the driver load but I have an
> error in unloading it.

According to a previous post on this list, you have been hacking the code
yourself, so please don't complain about the errors you get as a
consequence of this.

The I/O region conflict error you have is absolutely not related to the
reset change, it's much older. It's caused by PNPACPI since 2.6.10,
and has been fixed recently. See bug #4014 for additional information:
  http://bugzilla.kernel.org/show_bug.cgi?id@14
If you don't want to upgrade kernels, the workaround is to disable
PNPACPI, either when configuring your kernel or on the boot command line
(pnpacpi=off).

Thanks,
--
Jean Delvare

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Jacques Facquet]

Le Mercredi 9 Novembre 2005 12:02, Jean Delvare a ?crit :
> Hi Jacques,
Hi,

> On 2005-11-08, Jacques Facquet wrote:
> > This solved my problem too.
> > dmesg
> > Trying to free nonexistent resource <00000290-00000297>
> > (after reloading the driver)
> >
> > w83627hf 9191-0290: If reset=1 solved a problem you were having,
> > please report!
> >
> > Soltek QBic EQ-3401A-V2
> >
> > request_region(address, WINB_EXTENT, w83627hf_driver.name) return
> > an error, without checking this error, the driver load but I have
> > an error in unloading it.
>
> According to a previous post on this list, you have been hacking
> the code yourself, so please don't complain about the errors you
> get as a consequence of this.
Sure, it's not a complaint, sorry if you took it as.

> The I/O region conflict error you have is absolutely not related to
> the reset change, it's much older. It's caused by PNPACPI since
> 2.6.10, and has been fixed recently. See bug #4014 for additional
> information: http://bugzilla.kernel.org/show_bug.cgi?id@14
> If you don't want to upgrade kernels, the workaround is to disable
> PNPACPI, either when configuring your kernel or on the boot command
> line (pnpacpi=off).
Thank you for the link, I'll compile my kernel again, without my ugly 
hack.


-- 
Jacques Facquet.

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Stephen Kitt]

On Tue, 8 Nov 2005 09:23:28 +0100, "Eric Pascal" <Eric.Pascal@itesoft.com>
wrote:
> 	I have been submitting a patch to enable Fan speed control on my
> P4P800, and if you disable Q-Fan in the BIOS it work perfectly, you just
> set the temperature you want, the tolerance and the step and it works
> perfectly, don't need to rely on any tool like Speedfan on Windows to set
> the speed of my fan. The patch is being tested and modified to comply with
> lm-sensors standard. But if you are interested I can send you the patch
> that works great.

That would be great, thanks.

I realise now that my first mail was somewhat hasty, and in fact my setup is
(was) so unusual that it probably doesn't justify keeping reset=1. I imagine
most people who set Q-Fan up in their BIOS would want its fan control to
remain after booting, and those people who want to use software-based fan
control would simply disable Q-Fan altogether! Furthermore if the controller
can be switched from one mode to another at run-time, resetting it would
become unnecessary (or rather, subsumed by the mode switching), wouldn't it?

Regards,

Stephen

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Jean Delvare]

Hi Stephen, Eric,

> > I have been submitting a patch to enable Fan speed control on my
> > P4P800, and if you disable Q-Fan in the BIOS it work perfectly, you
> > just set the temperature you want, the tolerance and the step and it
> > works perfectly, don't need to rely on any tool like Speedfan on
> > Windows to set the speed of my fan. The patch is being tested and
> > modified to comply with lm-sensors standard. But if you are
> > interested I can send you the patch that works great.

I'm a bit worried by the "if you disable Q-Fan in the BIOS" condition.
It should work even with it enabled.

Anyway, Eric, I am still waiting for you to post the latest version of
your patch so that we can improve it.

> I realise now that my first mail was somewhat hasty, and in fact my setup
> is (was) so unusual that it probably doesn't justify keeping reset=1. I
> imagine most people who set Q-Fan up in their BIOS would want its fan
> control to remain after booting, and those people who want to use
> software-based fan control would simply disable Q-Fan altogether!

Except that some boards do not let you disable the automatic fan speed
control.

> Furthermore if the controller can be switched from one mode to another
> at run-time, resetting it would become unnecessary (or rather, subsumed
> by the mode switching), wouldn't it?

My point exactly. I still want to remove the reset parameter in the long
run, but I think we need to merge Eric's patch (after rework) before we
do.

Thanks,
--
Jean Delvare

[lm-sensors] reset=1 required for PWM control on Asus P4P800

[Eric Pascal]

It works with 2.6.14rc5

-----Message d'origine-----
De : Jean Delvare [mailto:khali@linux-fr.org]
Envoy? : jeudi 10 novembre 2005 15:50
? : lists@sk2.org; Eric Pascal
Cc : LM Sensors
Objet : Re: [lm-sensors] reset=1 required for PWM control on Asus P4P800
Deluxe



Hi Stephen, Eric,

> > I have been submitting a patch to enable Fan speed control on my
> > P4P800, and if you disable Q-Fan in the BIOS it work perfectly, you
> > just set the temperature you want, the tolerance and the step and it
> > works perfectly, don't need to rely on any tool like Speedfan on
> > Windows to set the speed of my fan. The patch is being tested and
> > modified to comply with lm-sensors standard. But if you are
> > interested I can send you the patch that works great.

I'm a bit worried by the "if you disable Q-Fan in the BIOS" condition.
It should work even with it enabled.

Anyway, Eric, I am still waiting for you to post the latest version of
your patch so that we can improve it.

> I realise now that my first mail was somewhat hasty, and in fact my setup
> is (was) so unusual that it probably doesn't justify keeping reset=1. I
> imagine most people who set Q-Fan up in their BIOS would want its fan
> control to remain after booting, and those people who want to use
> software-based fan control would simply disable Q-Fan altogether!

Except that some boards do not let you disable the automatic fan speed
control.

> Furthermore if the controller can be switched from one mode to another
> at run-time, resetting it would become unnecessary (or rather, subsumed
> by the mode switching), wouldn't it?

My point exactly. I still want to remove the reset parameter in the long
run, but I think we need to merge Eric's patch (after rework) before we
do.

Thanks,
--
Jean Delvare

[lm-sensors] reset=1 required for PWM control on Asus P4P800 Deluxe

[M Rachao]

Hi, I found this page through google.  Can you tell me where to find the 
windows version of the 'patch' that enables me to control the cpu fan 
speed ?
Im really glad you wrote it.
Thanks
-Manuel