speed improvement with kernel 4.2.5 / 4.3.3 / 4.6.6

[uelpenich]

I googled some interesting information:
http://forum.nas-central.org/viewtopic.php?f=240&t=5791
the fan speed is set by i2c bus, gpio is only used to signal an alarm.

This command sets the fan speed:

root@2big2:/ # cd /sys/bus/i2c/devices/0-003e/hwmon/hwmon0
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # echo 0 > pwm1
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # echo 0 > pwm1
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # echo 10 > pwm1
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # echo 255 > pwm1
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # echo 256 > pwm1
sh: write error: Invalid argument
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 #

0 = fan off
10 = minimal speed to start the fan
255 = maximal fan speed

http://natisbad.org/NAS5/#hw-fan-controller
The fan controller chip is a G782.

[fvdw]

interesting uelpenich
I think you mean G762 instead of G782.
But I dont think there is a controller G762 on board as the driver is incorperated in the kernel but not loaded. On the 5big2 it is loaded (the G762) and the gpio-fan not.

But it might very well be that the fan can be controlled via i2c bus, it seems gpio-fan (hwmon) is using it. Luckily I initialized this i2c device by default for 5big2 and 2big2. On 5big2 the g762 driver uses the same i2c device 0-003e

In the folder /sys/bus/i2c/devices/0-003e/hwmon/hwmon0
There must be als a file with name "name", what is the content

can you post the content of the cd /sys/bus/i2c/devices/0-003e/hwmon/hwmon0 folder ? (ls -al)

need to do some reading

[fvdw]

also there must a symlink "driver" in this folder to which file is that pointing to ?

[uelpenich]

I think I have got it:

I think you mean G762 instead of G782.

You are right, it is a typing error.

Find the description of the G762 driver here:
https://github.com/MISL-EBU-System-SW/mainline-public/blob/master/Documentation/hwmon/g762
I think the driver G762 is present.

This is the difference between kernel 3.14.2 and 4.3.3:

There must be als a file with name "name"

The path to the files is different:

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3.14.2  /sys/bus/i2c/devices/0-003e
4.3.3   /sys/bus/i2c/devices/0-003e/hwmon/hwmon0

There must be als a file with name "name", what is the content

g762

More interesting is the content of the file pwm1 (fan speed [0 .. 255]):

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with kernel 3.14.2 it is 0
with kernel 4.3.3 it is 18

That means the fan runs with a speed of 18 out of 255, which is not full speed as I supposed. This is better than 0 as in 3.14.2 kernels.

All other files contain the same values. Since the fan is a 2-wire fan the G762 controller works in open-loop mode
(pwm1_enable=1; pwm1_mode=1)

also there must a symlink "driver" in this folder to which file is that pointing to ?

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root@2big2:/sys/bus/i2c/devices/0-003e # ls -l
total 0
lrwxrwxrwx  1 root root    0 2016-01-04 22:36 driver -> ../../../../../bus/i2c/drivers/g762
drwxr-xr-x  3 root root    0 2016-01-04 22:34 hwmon
-r--r--r--  1 root root 4096 2016-01-04 22:36 modalias
-r--r--r--  1 root root 4096 2016-01-04 22:36 name
drwxr-xr-x  2 root root    0 2016-01-04 22:36 power
lrwxrwxrwx  1 root root    0 2016-01-04 22:36 subsystem -> ../../../../../bus/i2c
-rw-r--r--  1 root root 4096 2016-01-04 22:34 uevent
root@2big2:/sys/bus/i2c/devices/0-003e #

can you post the content of the cd /sys/bus/i2c/devices/0-003e/hwmon/hwmon0 folder ? (ls -al)

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root@2big2:/sys/bus/i2c/devices/0-003e/hwmon # cd hwmon0
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 # ls -l
total 0
lrwxrwxrwx  1 root root    0 2016-01-04 22:36 device -> ../../../0-003e
-r--r--r--  1 root root 4096 2016-01-04 22:36 fan1_alarm
-rw-r--r--  1 root root 4096 2016-01-04 22:36 fan1_div
-r--r--r--  1 root root 4096 2016-01-04 22:36 fan1_fault
-r--r--r--  1 root root 4096 2016-01-04 22:36 fan1_input
-rw-r--r--  1 root root 4096 2016-01-04 22:36 fan1_pulses
-rw-r--r--  1 root root 4096 2016-01-04 22:36 fan1_target
-r--r--r--  1 root root 4096 2016-01-04 22:36 name
drwxr-xr-x  2 root root    0 2016-01-04 22:36 power
-rw-r--r--  1 root root 4096 2016-01-04 22:36 pwm1
-rw-r--r--  1 root root 4096 2016-01-04 22:36 pwm1_enable
-rw-r--r--  1 root root 4096 2016-01-04 22:36 pwm1_mode
lrwxrwxrwx  1 root root    0 2016-01-04 22:36 subsystem -> ../../../../../../../class/hwmon
-rw-r--r--  1 root root 4096 2016-01-04 22:34 uevent
root@2big2:/sys/bus/i2c/devices/0-003e/hwmon/hwmon0 #

Whats about a temperature sensor and a control loop to set the fan speed?

[fvdw]

funny , I checked my 5big2 when running kernel 4.3.3 #6 and it also now uses /sys/bus/i2c/devices/0-003e/hwmon/hwmon0 as directory, instead of /sys/bus/i2c/devices/0-003e/ :shock:

this is the content

5big2-kernel-433-6.JPG

so indeed as well 2big2 as 5big2 seems to use the g762 driver, and if the content of the folder is the same so then it will be easy to adapt the fan daemon we use on the 5big2 for use on 2big2 also (based on actual disk temp measurements) :punk

need to find out why it changed the folder from /sys/bus/i2c/devices/0-003e/ to /sys/bus/i2c/devices/0-003e/hwmon/hwmon0 as now the fan daemon will not work on the 5big2 as well as it uses folder /sys/bus/i2c/devices/0-003e/ to control the speed

[fvdw]

seems the location change is because of a kernel modification

https://lkml.org/lkml/2014/5/5/420

So I will need to add a check in the fan daemon and rcS script to find the right directory to have backwards compatibility :dry

[wd9895]

Hi fvdw,

will you integrate the new kernel in the next fw release or patch ?

[fvdw]

Yes that is the intention also the fan daemon will be updated to suport old and new kernel

[fvdw]

I updated the fan daemon so it is compatible with the 4.3.3 and also the older kernels

To use it you need to replace the file fan5big in the the folder /bin_cab
After installing it you should be able to run the 4.3.3 kernel with an working fan daemon

To be able to replace the file you need to kill the running fan daemon first

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killall fan-d

Be aware that if you kill the fan daemon that the fan is off,
reboot the nas after you replaced the fan daemon file to get the daemon active again
After reboot you can check if the daemon is running again by using this command

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ps -ef | grep fan-d

You should get this as response

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root@fvdwsl-5big2:/ # ps -ef | grep fan-d
root       931     1  0 22:59 ?        00:00:00 /usr/sbin/fan-d
root      2411  2397  0 23:16 pts/0    00:00:00 grep fan-d
root@fvdwsl-5big2:/ #

[fvdw]

seems the kernel 4.3.3 #6 may fail to mount ext3 root file systems due to changes made in the linux kernel (ext3 driver is removed, the ext4 driver handling ext3 now, sometimes the root file system is now mounted as ext2 which is wrong as it cannot handle the journal).
The nasty thing is it it happens random, most of the time the mount is ok but sometimes not

attached a new version that solve this issue, only ext4 driver present which can also handle ext3 file systems

I recommend to use this new version (#7) for further tests

---edit there is a new version with a patch for bug in mv643 driver
viewtopic.php?f=4&t=2345&p=22201#p22201