Re: How does rfkill work?

[Marcel Holtmann <marcel@holtmann.org>]

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?

Regards

Marcel