Bug 80507

Summary:	Cannot set pwm1 above 80 on GeForce 9600 GT, 10de:0622
Product:	xorg	Reporter:	Adam Williamson <adamw>
Component:	Driver/nouveau	Assignee:	Nouveau Project <nouveau>
Status:	RESOLVED NOTABUG	QA Contact:	Xorg Project Team <xorg-team>
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Adam Williamson 2014-06-25 01:13:08 UTC

It seems like the /sys/class/drm/card0/device/hwmon/hwmon0/pwm1 value for my GeForce 9600 GT (10de:0622) will never go above 80.

If I do echo 1 > pwm1_enable (to set it to manual control), then try echoing values to pwm1, it basically acts as if any value above 80 is identical to 80.

[root@adam hwmon0]# pwd
/sys/class/drm/card0/device/hwmon/hwmon0
[root@adam hwmon0]# echo 79 > pwm1
[root@adam hwmon0]# cat pwm1
79
[root@adam hwmon0]# echo 81 > pwm1
[root@adam hwmon0]# cat pwm1
80
[root@adam hwmon0]# echo 100 > pwm1
[root@adam hwmon0]# cat pwm1
80
[root@adam hwmon0]# echo 100000 > pwm1
[root@adam hwmon0]# cat pwm1
80
[root@adam hwmon0]# echo 30 > pwm1
[root@adam hwmon0]# cat pwm1
30
[root@adam hwmon0]# echo 100000 > pwm1
[root@adam hwmon0]# cat pwm1
80

Comment 1 Adam Williamson 2014-06-25 01:13:59 UTC

Sorry, this is with:

[root@adam hwmon0]# uname -r
3.16.0-0.rc2.git0.1.fc21.x86_64

Fedora Rawhide.

Comment 2 Adam Williamson 2014-06-25 01:18:07 UTC

nouveau.debug="PHERM=debug" logs the values as they change, but doesn't give any other useful information, it doesn't provide any handy smoking gun hints as to what's going on.

Comment 3 Martin Peres 2014-06-25 07:24:12 UTC

(In reply to comment #2)
> nouveau.debug="PHERM=debug" logs the values as they change, but doesn't give
> any other useful information, it doesn't provide any handy smoking gun hints
> as to what's going on.

cat pwm1_max

I guess your vbios states the maximum fan speed is 80%, hence why Nouveau isn't allowing you to set anything higher.

Please tell us if pwm1_max is set to 80 so as we close this as not a bug :)

Comment 4 Adam Williamson 2014-06-25 15:14:14 UTC

Ben initially thought it was a bug as he thought he had a vbios from the same card indicating it should go higher, but apparently he may have been looking at the wrong one. pwm1_max is 80, yeah. apparently ideally I should send the vbios to verify, but Fedora's kernel config doesn't seem to provide the necessary bits...I only filed this as Ben thought it was a bug, so let's just close it for now.

Comment 5 Martin Peres 2014-06-25 16:35:39 UTC

(In reply to comment #4)
> Ben initially thought it was a bug as he thought he had a vbios from the
> same card indicating it should go higher, but apparently he may have been
> looking at the wrong one. pwm1_max is 80, yeah. apparently ideally I should
> send the vbios to verify, but Fedora's kernel config doesn't seem to provide
> the necessary bits...I only filed this as Ben thought it was a bug, so let's
> just close it for now.

This is not the first vbios I see with pwm_max set to 80, hence why I thought straight away about this. 

You can force the pwm1_max to 100 if you really want to make it go to 100%, but I wouldn't do that.

Anyway, thanks for the quick response!

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.