Problem modifying file in /sys

[hydrurga]

I am not sure where I should be posting this, but as I am Linux newbie...

In order to get wireless to work on my Amilo Li1718 under Puppy 4.1.1 (full hard disk install), I need to load a module called acer-rmi to do two things: (i) enable the wireless adapter, (ii) switch on the PC's wireless button. I therefore run 'modprobe acer-rmi' which appears to work fine and enables the wireless adapter.

The problem is that, in order to switch on the button, I have been advised to change the contents of a file called 'wireless' created by that module in a /sys subdirectory, using the command 'echo 1 > /sys/devices/platform/acer-wmi/wireless'. Simply, this doesn't work, and any attempts to modify this file fail. In fact the original file, as created by the modprobe, is created as a 4096 byte sized file but then as soon as I try to write to it or modify it in any way it becomes a 0 byte sized file. In fact, experimentation has shown that I cannot change any file in the /sys branch. Trying to load the module with 'modprobe acer-rmi wireless=1' does not work.

I have searched about and noticed that many people seem to have successfully been able to echo data into files in /sys. Why is it that I can't?

Pete

[oz]

Welcome to the forums!

You must have root permissions to edit files outside of your /home directory.

Open a terminal, su to root, then try running your edit commands:

su

...enter root password when requested

You might need to put sudo before the command instead of using su if your distro uses it:

sudo command_name

[hydrurga]

Welcome to the forums!

You must have root permissions to edit files outside of your /home directory.

Open a terminal, su to root, then try running your edit commands:

su

...enter root password when requested

You might need to put sudo before the command instead of using su if your distro uses it:

sudo command_name

Thanks Osar. Puppy is one of those rare distros where everyone is a superuser (root) by default.

[oz]

Thanks Osar. Puppy is one of those rare distros where everyone is a superuser (root) by default.

Thanks for the info... it's been so long since I last ran Puppy that I didn't even remember that being the case. Sorry that I can't think of anything else to suggest, but maybe a current Puppy user will chime in with some good advice for you. Let us know how it goes.

[hydrurga]

Thanks for the info... it's been so long since I last ran Puppy that I didn't even remember that being the case. Sorry that I can't think of anything else to suggest, but maybe a current Puppy user will chime in with some good advice for you. Let us know how it goes.

No problem at all Oz! I must admit that I've also posted this query in the Puppy forum and had no help with it all. Although I really like Puppy I reckon I might move to a more supportive and friendlier distro. In the end, I imagine that my problem will come down to something banal and obvious but as a newbie I just can't see it...

[hydrurga]

Here is my command sequence for the problem described in this thread. My apologies for incorrectly typing acer-rmi instead of acer-wmi in my OP.

# modprobe acer-wmi

# ls -l /sys/devices/platform/acer-wmi/wireless

-rw-rw-rw- 1 root root 4096 2008-11-28 01:00 /sys/devices/platform/acer-wmi/wireless

#cat /sys/devices/platform/acer-wmi/wireless

0

# echo 1 > /sys/devices/platform/acer-wmi/wireless

# ls -l /sys/devices/platform/acer-wmi/wireless

-rw-rw-rw- 1 root root 0 2008-11-28 01:02 /sys/devices/platform/acer-wmi/wireless

# cat /sys/devices/platform/acer-wmi/wireless

0

Pete

[dxqcanada]

Do you get any hints from your "dmesg" command output concerning the wireless interface ?

[hydrurga]

Do you get any hints from your "dmesg" command output concerning the wireless interface ?

Hi dxqcanada, many thanks for posting. Here's an excerpt from the dmesg output on boot (from the first time that it mentions ath_hal until the end). If you can find anything in there...

ath_hal: module license 'Proprietary' taints kernel.
AR5210, AR5211, AR5212, AR5416, RF5111, RF5112, RF2413, RF5413, RF2133, RF2425, RF2417)
PCI: Enabling device 0000:02:00.0 (0000 -> 0002)
ACPI: PCI Interrupt 0000:02:00.0[A] -> GSI 16 (level, low) -> IRQ 16
PCI: Setting latency timer of device 0000:02:00.0 to 64
MadWifi: ath_attach: Switching rfkill capability off.
wifi0: Atheros AR2425 chip found (MAC 14.2, PHY SChip 7.0, Radio 10.2)
ath_pci: wifi0: Atheros 5424/2424: mem=0xc0000000, irq=16
lp: driver loaded but no devices found
ACPI: EC: missing address confirmation, don't expect it any longer.
ACPI: EC: missing write data confirmation, don't expect it any longer.

Then, "modprobe acer-wmi" produces:

acer-wmi: Acer Laptop ACPI-WMI Extras version 0.1
Registered led device: acer-wmi::mail

Pete

[dxqcanada]

Try this:

# rmmod ath_pci
# modprobe ath_pci rfkill=0