Re: LED (leds_hp_disk) causes BUG: scheduling while atomic

[Pavel Machek <pavel@suse.cz>]

Hi!

> I'm not sure if I should send this email to LKML, because it doesn't
> seem to important, and the traffic there seems high. If you are not the
> correct maintainer, or if I should send it there anyway, please tell me.
> 
> Update: I sent this letter first to Helge Deller <deller@gmx.de>, he
> told me to mail to you.

Yep, that's right, I'm responsible. LKML is indeed right thing to Cc:.

> I have a HP Compaq nc2400 notebook, and having recently installed 2.6.28
> (gentoo patchset, self configured), I have observed the following:
> 
> When {I manually, udev automatically} load the leds_hp_disk module, my
> disk-led flashes regularly _without_ disk activity. When I look at my
> dmesg I see the following:

Yes, that's a (mis-feature).

> [  724.376881] BUG: scheduling while atomic: swapper/0/0x10000100
> [  724.376886] Modules linked in: leds_hp_disk i915 drm snd_pcm_oss

And that's a bug. I know what causes it, but i don't have right fix
yet.

If you are interested, take latest -mm (mmotm from userweb) and apply
this manually:

--- linux-mm/drivers/hwmon/hp_accel.c   2009-01-06 10:54:40.000000000
+0100
+++ linux/drivers/hwmon/hp_accel.c      2008-12-10 09:36:21.000000000
+0100
@@ -174,11 +174,35 @@
 }
 
 static struct led_classdev hpled_led = {
-       .name                   = "hp:red:hddprotection",
-       .default_trigger        = "heartbeat",
+       .name                   = "hp:red:hddprotect",
+       .default_trigger        = "none",
        .brightness_set         = hpled_set,
 };


...led will stop blinking, and messages will be gone. (But note that
if you turn on heartbeat or similar trigger, you'll still get the
"scheduling in interrupt" nastyness...)
									Pavel
-- 
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