Bug 42885

Summary: Mute LED indicator is always in "off" (muted) state
Product: Drivers Reporter: Morse (radist.morse)
Component: Sound(ALSA)Assignee: Jaroslav Kysela (perex)
Status: RESOLVED INVALID    
Severity: low CC: tiwai
Priority: P1    
Hardware: All   
OS: Linux   
URL: https://bugs.gentoo.org/show_bug.cgi?id=388037 , https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5469
Kernel Version: 3.2.9 Subsystem:
Regression: No Bisected commit-id:

Description Morse 2012-03-07 19:23:57 UTC 
Mute button itself works ok.

lspci:

00:1b.0 Audio device [0403]: Intel Corporation Cougar Point High Definition Audio Controller [8086:1c20] (rev 04)
	Subsystem: Hewlett-Packard Company Device [103c:1630]
	Kernel driver in use: snd_hda_intel

alsa script output:

http://www.alsa-project.org/db/?f=4ba2b8e1aca862ad3d43cc6e05fb94a2f4058d1f

Technically, LED is working: I can activate it manually with HDA analyzer by switching on flags "enabled" and "dir-out" on GPIO IO[0]. But they are always "off" by default.

In ubuntu led indicator is working ok.
Comment 1 Takashi Iwai 2012-03-08 07:01:25 UTC 
It's likely a BIOS problem.  The recent patch_sigmatel relies on DMI string "HP_Mute_LED" to figure out whether the mute LED is present and which GPIO is used.

Check your DMI strings and see whether this string is provided and what it is.
It should be like "HP_Mute_LED_0_0".
Comment 2 Morse 2012-03-08 11:59:13 UTC 
Nope, the string is there

Handle 0x0011, DMI type 11, 5 bytes
OEM Strings
	String 1: ABS 70/71 79 7A 7B 7C
	String 2: CSM v01.51
	String 3: HP_Mute_LED_0_0
	String 4: www.hp.com
Comment 3 Takashi Iwai 2012-03-08 12:00:41 UTC 
Then check whether you built a kernel with CONFIG_SND_HDA_POWER_SAVE=y.  The mute-LED control is (ab-)using the powersave hook for checking the status.
Comment 4 Morse 2012-03-08 12:06:36 UTC 
# CONFIG_SND_HDA_POWER_SAVE is not set

The name "Aggressive power-saving on HD-audio" sounds quite scary, that's why I didn't enable it. Should I also set the time-out to something other then 0?
Comment 5 Takashi Iwai 2012-03-08 12:57:46 UTC 
The value doesn't matter.
Comment 6 Morse 2012-03-08 14:56:50 UTC 
Yes, that fixed it. And since sigmatel codec is (ab-)using powersave anyway, you should consider making it a dependency.