Fan speed after boot with 1.0 release

[Bill Rosenberg]

Joao,

I see a minor issue with the fan behavior in the 1.0 release. This is on a 323-B1. What I see is that after boot, the fan pwm is set to 127 no matter what I have the sysctrl fan configuration set to. Eventually, the settings from sysctrl.conf start to be used.

This is a sample of the fantemp log from boot:

Oct 16 21:36:41 sys_temp=38     disk_temp=0     pwm=127 fan=3840
Oct 16 22:39:33 sys_temp=38     disk_temp=0     pwm=0   fan=0
Oct 16 22:41:34 sys_temp=39     disk_temp=0     pwm=0   fan=0
Oct 16 22:44:49 sys_temp=40     disk_temp=0     pwm=0   fan=0
Oct 16 23:01:50 sys_temp=40     disk_temp=0     pwm=73  fan=2715
Oct 16 23:04:05 sys_temp=39     disk_temp=0     pwm=57  fan=2469
Oct 16 23:09:21 sys_temp=38     disk_temp=0     pwm=57  fan=2469

sysctrl.conf is:

hi_fan="5000"
hi_temp="50"
lo_fan="2500"
lo_temp="40"
fan_off_temp="39"
max_fan_speed="6000"
hist_temp="1"
warn_temp="52"
crit_temp="54"
crit_temp_command="/usr/sbin/poweroff"
mail="1"
recovery="1"

I should never see the higher fan speed of pwm=127 given my temps. The amount of time it takes to get to normal operation seems to vary. It is about 3 minutes in the example above but I have seen both shorter and longer delays.

Any ideas what is happening?

Bill

[João Cardoso]

Hi Bill

On Tuesday, 17 October 2017 05:39:58 UTC+1, Bill Rosenberg wrote:

Joao,

I see a minor issue with the fan behavior in the 1.0 release. This is on a 323-B1. What I see is that after boot, the fan pwm is set to 127 no matter what I have the sysctrl fan configuration set to.

It is not a bug, its a feature.

The fan is set at half speed early in the boot (rcS), in the case that something wrong happens during the boot process and sysctrl does not starts or dies. 

For the same reason sysctrl leaves the fan at half speed when it quits (such as stop all processes, power down or reboot...)

 

Eventually, the settings from sysctrl.conf start to be used.

This is a sample of the fantemp log from boot:

Oct 16 21:36:41 sys_temp=38     disk_temp=0     pwm=127 fan=3840
Oct 16 22:39:33 sys_temp=38     disk_temp=0     pwm=0   fan=0
Oct 16 22:41:34 sys_temp=39     disk_temp=0     pwm=0   fan=0
Oct 16 22:44:49 sys_temp=40     disk_temp=0     pwm=0   fan=0
Oct 16 23:01:50 sys_temp=40     disk_temp=0     pwm=73  fan=2715
Oct 16 23:04:05 sys_temp=39     disk_temp=0     pwm=57  fan=2469
Oct 16 23:09:21 sys_temp=38     disk_temp=0     pwm=57  fan=2469

sysctrl.conf is:

hi_fan="5000"
hi_temp="50"
lo_fan="2500"
lo_temp="40"
fan_off_temp="39"
max_fan_speed="6000"
hist_temp="1"
warn_temp="52"
crit_temp="54"
crit_temp_command="/usr/sbin/poweroff"
mail="1"
recovery="1"

I should never see the higher fan speed of pwm=127 given my temps. The amount of time it takes to get to normal operation seems to vary. It is about 3 minutes in the example above but I have seen both shorter and longer delays.

The time that sysctrl takes to take over the fan speed depends on the current system temperature and the fan/temp control window settings. That could be better handled, but I think that's reasonable as it is now.

Thanks

Joao

[Bill Rosenberg]

Thanks. I did not notice this behavior on RC5 and earlier, but now understand this is normal.