Re: How does rfkill work?

[Larry Finger <Larry.Finger@lwfinger.net>]

Marcel Holtmann wrote:
> Hi Larry,
> 
>>> On Thu, 2009-04-02 at 20:48 +0200, Johannes Berg wrote:
>>>
>>> Could you try something for me?
>>>
>>> In drivers/leds/led-triggers.c in led_trigger_show you have
>>>
>>>         list_for_each_entry(trig, &trigger_list, next_trig) {
>>> +		printk(KERN_DEBUG "available trigger: %s\n", trig->name);
>>>                 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
>>>                                                         trig->name))
>>>                         len += sprintf(buf+len, "[%s] ", trig->name);
>>>                 else
>>>                         len += sprintf(buf+len, "%s ", trig->name);
>>>         }
>>>
>>> could you do the modification, with a kernel that has the TRIG_NAME_MAX
>>> set to 50, and see what it prints? I'm completely confused by this
>>> failure mode since the garbage you get is actually put into brackets, so
>>> it seems the strcmp() is returning 0 which seems odd.
>> Have I told you that I hate things that appear to be intermittent?
>>
>> I added the printk, returned TRIG_NAME_MAX to 50, rebuilt and rebooted. This
>> time I got
>>
>> ~/wireless-testing> cat /sys/class/leds/b43legacy-phy0\:\:rad/trigger
>> none ide-disk ADP1-online BAT0-charging-or-full BAT0-charging BAT0-full phy0rx
>> phy0tx phy0assoc phy0radio [rfkill0]
>> ~/wireless-testing> dmesg | grep available
>> available trigger: ide-disk
>> available trigger: ADP1-online
>> available trigger: BAT0-charging-or-full
>> available trigger: BAT0-charging
>> available trigger: BAT0-full
>> available trigger: phy0rx
>> available trigger: phy0tx
>> available trigger: phy0assoc
>> available trigger: phy0radio
>> available trigger: rfkill0
>>
>> I'll leave the printk in place for the moment.
>>
>> The name is being truncated by "#define BUS_ID_SIZE 20" in
>> include/linux/device.h. As changing that define would be pretty invasive, I plan
>> to use a shorter name when the LED is registered.
> 
> I am under the impression that all these limitations are going away. Did
> you talk to Kay or Greg about this?

No, I have not approached them about this matter. Based on this exchange, I will
find out from them.

To answer your previous question, this is a 2.6.29 kernel from wireless-testing.

Thanks,

Larry