sensors command is not getting executed in Ubuntu 15.10 on PowerNV 8335-GTA Hardware

[bugproxy]

---Problem Description---
sensors command is not getting executed in Ubuntu 15.10 on PowerNV 8335-GTA Hardware

---uname output---
Linux tul8fp 3.19.0-22-generic #22-Ubuntu SMP Tue Jun 16 17:15:17 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux

Machine Type = P8

---Steps to Reproduce---
Install a PowerNV 8335-GTA machine with Ubuntu 15.10 ISO.
Then load the kernel module ibmpowernv on the same.

root@tul8fp:~# sensors
No sensors found!
Make sure you loaded all the kernel drivers you need.
Try sensors-detect to find out which these are.

root@tul8fp:~# sensors-detect
# sensors-detect revision 6209 (2014-01-14 22:51:58 +0100)
# DMI data unavailable, please consider installing dmidecode 2.7
# or later for better results.

This program will help you determine which kernel modules you need
to load to use lm_sensors most effectively. It is generally safe
and recommended to accept the default answers to all questions,
unless you know what you're doing.

Some south bridges, CPUs or memory controllers contain embedded sensors.
Do you want to scan for them? This is totally safe. (YES/no): YES
modprobe: FATAL: Module cpuid not found.
Failed to load module cpuid.
Silicon Integrated Systems SIS5595... No
VIA VT82C686 Integrated Sensors... No
VIA VT8231 Integrated Sensors... No
AMD K8 thermal sensors... No
AMD Family 10h thermal sensors... No
AMD Family 11h thermal sensors... No
AMD Family 12h and 14h thermal sensors... No
AMD Family 15h thermal sensors... No
AMD Family 15h power sensors... No
AMD Family 16h power sensors... No
Intel digital thermal sensor... No
Intel AMB FB-DIMM thermal sensor... No
VIA C7 thermal sensor... No
VIA Nano thermal sensor... No

Lastly, we can probe the I2C/SMBus adapters for connected hardware
monitoring devices. This is the most risky part, and while it works
reasonably well on most systems, it has been reported to cause trouble
on some systems.
Do you want to probe the I2C/SMBus adapters now? (YES/no): YES
Sorry, no supported PCI bus adapters found.

Next adapter: p8_00000008_e0p0 (i2c-0)
Do you want to scan it? (YES/no/selectively): YES
Client found at address 0x50
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)
Client found at address 0x51
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)

Next adapter: p8_00000008_e0p1 (i2c-1)
Do you want to scan it? (YES/no/selectively): YES
Client found at address 0x50
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)
Client found at address 0x51
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)

Next adapter: p8_00000000_e0p0 (i2c-2)
Do you want to scan it? (YES/no/selectively): YES
Client found at address 0x50
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)
Client found at address 0x51
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)

Next adapter: p8_00000000_e0p1 (i2c-3)
Do you want to scan it? (YES/no/selectively): YES
Client found at address 0x50
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)
Client found at address 0x51
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)

Next adapter: p8_00000000_e1p2 (i2c-4)
Do you want to scan it? (YES/no/selectively): YES
Client found at address 0x50
Handled by driver `at24' (already loaded), chip type `24c128'
    (note: this is probably NOT a sensor chip!)

Next adapter: AST i2c bit bus (i2c-5)
Do you want to scan it? (yes/NO/selectively): YES

Sorry, no sensors were detected.
Either your system has no sensors, or they are not supported, or
they are connected to an I2C or SMBus adapter that is not
supported. If you find out what chips are on your board, check
http://www.lm-sensors.org/wiki/Devices for driver status.

root@tul8fp:~# cat /boot/config-3.19.0-22-generic | grep -i sensor | grep -i ibm
CONFIG_SENSORS_IBMAEM=m
CONFIG_SENSORS_IBMPEX=m
CONFIG_SENSORS_IBMPOWERNV=m

 The issue is that there are upstream commits missing in Ubuntu 15.10 which are required here, these patches were specifically added to enable the sensors support on the OpenPower systems. So, they should ideally be backported for 'sensors' command to work.
To quickly verify this, I picked the upstream driver source file (drivers/hwmon/ibmpowernv.c), built it as modules as below:
ubuntu@tul8fp:~/module$ cat Makefile
obj-m := ibmpowernv.o

all:
 make -C /lib/modules//build M= modules

clean:
 make -C /lib/modules//build M= clean
ubuntu@tul8fp:~/module$ make
.....
ubuntu@tul8fp:~/module$ sudo insmod ibmpowernv.ko
........
ubuntu@tul8fp:~/module$ sensors
ibmpowernv-isa-0000
Adapter: ISA adapter
Core 8-15: +1328545.8?C
Core 16-23: +1328545.8?C
Core 24-31: +1328545.8?C
Core 32-39: +1328545.8?C
Core 40-47: +1328545.8?C
<snip>

IAfter having a discussion with Neelesh, he has referred to the below upstream commit id's of the patches required for back-porting for Ubuntu 15.10 so that sensors could be enabled.

8416915 hwmon: (ibmpowernv) Fix build error seen for some configurations
3df2f59 hwmon: (ibmpowernv) pretty print labels
2bcd378 hwmon: (ibmpowernv) add a label attribute
1468163 hwmon: (ibmpowernv) add support for the new device tree
9e4f74b hwmon: (ibmpowernv) add a helper routine create_hwmon_attr
fcaf57b hwmon: (ibmpowernv) do not use the OPAL index for hwmon attribute names
f9f54f1 hwmon: (ibmpowernv) change create_hwmon_attr_name() prototype
ccc9ac6 hwmon: (ibmpowernv) add a convert_opal_attr_name() routine
c4ad472 hwmon: (ibmpowernv) add a get_sensor_type() routine
9612461 hwmon: (ibmpowernv) replace AMBIENT_TEMP by TEMP

So, Ubuntu is required to get all the above patches to be incorporated into 15.10.

[Chris J Arges (arges)]

All of these commits are in v3.18-rc4, and thus in 15.10's kernel.
I think the issue here is that you did not modprobe the module in the firstplace.
From a clean install do:
modprobe ibmpowernv

The reason this doesn't get autoloaded seems to be another issue here:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1452473

I looked into this a while back and it seems like there is a mismatch between the modalias and what OF provides.

Marking this a dup of that bug. Thanks

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2015-07-13 07:32 EDT-------
Patches apply correctly on the linux-image-3.19.0-22-generic when applied in the below order.
Please incorporate into 15.10 enable sensor command.

9612461 hwmon: (ibmpowernv) replace AMBIENT_TEMP by TEMP
c4ad472 hwmon: (ibmpowernv) add a get_sensor_type() routine
ccc9ac6 hwmon: (ibmpowernv) add a convert_opal_attr_name() routine
f9f54f1 hwmon: (ibmpowernv) change create_hwmon_attr_name() prototype
fcaf57b hwmon: (ibmpowernv) do not use the OPAL index for hwmon attribute names
9e4f74b hwmon: (ibmpowernv) add a helper routine create_hwmon_attr
1468163 hwmon: (ibmpowernv) add support for the new device tree
2bcd378 hwmon: (ibmpowernv) add a label attribute
3df2f59 hwmon: (ibmpowernv) pretty print labels
8416915 hwmon: (ibmpowernv) Fix build error seen for some configurations

Thank you.