Kernel 3.18.8 breaks 1-wire ?

[dbannon]

Since I upgraded my Raspberry Pi to the 3.18.8 K my 1-wire system is broken. Just went to 3.18.9 and same problem.

Its all about the new Device Tree stuff. I need to load kernel mods w1_gpio (and w1_therm). The default situation, that is out of the box config.txt, load apparently with out errors but are not functional. In particular, we cannot see /sys/bus/w1/devices/w1_bus_master1.

So, googling around, now need to tell system, via config.txt I want to use 1-wire. Cool, Arch's config.txt seems to have provided necessary config options, uncomment -
$this->bbcode_second_pass_code('', 'device_tree_overlay=w1-gpio-pullup
device_tree_param=gpiopin=4
device_tree_param=pullup=on
device_tree_param=extpullup=5')

and reboot. Now I do see /sys/bus/w1/devices/w1_bus_master1 but no files there representing the temp sensors I use. And, in dmesg I see -
$this->bbcode_second_pass_code('', '[ 8.869662] Driver for 1-wire Dallas network protocol.
[ 8.903004] w1-gpio onewire@0: gpio pin 4, external pullup pin 5, parasitic power 1
[ 8.942929] w1_add_master_device: set_pullup requires write_byte or touch_bit, disabling')
This really has nothing to do with the hardware I have connected, see same error message on another 'Pi with no hardware attached.

Any suggestions ?

David

[WarheadsSE]

$this->bbcode_second_pass_code('', '[ 8.942929] w1_add_master_device: set_pullup requires write_byte or touch_bit, disabling')
It seems you might be missing a parameter

[dbannon]

Well, a missing parameter ? Any suggestion what that is ?

I have uncommented the lines that config.txt tells me to uncomment. Nothing more or less.

David

[WarheadsSE]

config.txt comes from the foundation, and perhaps they missed something.

[dbannon]

Do you think that means its only been tested on Raspian then ? There was some discussion on the foundation lists on the topic, especially when 3.18.8 was released. Evidence is, once the correct parameters were set, it all worked again on Raspian. And 3.18.9 has a more structured config.txt.

I guess I have to build a raspian to test that myself, trouble is my network has taken a beating this month so will need to wait a bit. Sigh....

David

[dbannon]

Actually, think I owe the Device Tree people an apology, for what I thought if not what I said.

I found that I could disable DT https://github.com/raspberrypi/documentation/blob/master/configuration/device-tree.md and sure enough, the problem and the error message still exists. So must assume its somewhere between kernel and the w1_gpio module.

Messy, could be very messy.

David