Patch "ALSA: hda - Fix path power activation" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

ALSA: hda - Fix path power activation

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
alsa-hda-fix-path-power-activation.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Takashi Iwai <[email protected]>
Date: Mon, 24 Aug 2015 10:52:06 +0200
Subject: ALSA: hda - Fix path power activation

From: Takashi Iwai <[email protected]>

commit c7cd0ef66aade29e37ee08821a0e195ee776c6e6 upstream.

The widget power-saving code tries to turn up/down the power of each widget in the I/O paths that are modified at each jack plug/unplug. The recent report revealed that the power activation leaves some widgets unpowered after plugging. This is because snd_hda_activate_path() turns on path->active flag at the end of the function while the path power management is done before that. Then it's regarded as if nothing is active, and the driver turns off the power.

The fix is simply to set the flag at the beginning of the function, before trying to power up.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=102521

---
 sound/pci/hda/hda_generic.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

@@ -884,8 +884,7 @@ void snd_hda_activate_path(struct hda_co
 	struct hda_gen_spec *spec = codec->spec;
 	int i;
 
-	if (!enable)
-		path->active = false;
+	path->active = enable;
 
 	/* make sure the widget is powered up */
 	if (enable && (spec->power_down_unused || codec->power_save_node))

@@ -903,9 +902,6 @@ void snd_hda_activate_path(struct hda_co
 		if (has_amp_out(codec, path, i))
 			activate_amp_out(codec, path, i, enable);
 	}
-
-	if (enable)
-		path->active = true;
 }
 EXPORT_SYMBOL_GPL(snd_hda_activate_path);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/alsa-hda-fix-possible-null-dereference.patch queue-4.1/alsa-hda-fix-the-white-noise-on-dell-laptop.patch queue-4.1/alsa-usb-add-native-dsd-support-for-gustard-dac-x20u.patch queue-4.1/alsa-hda-fix-path-power-activation.patch queue-4.1/alsa-hda-check-all-inputs-for-is_active_nid_for_any.patch queue-4.1/alsa-usb-audio-fix-runtime-pm-unbalance.patch queue-4.1/alsa-hda-shutdown-cx20722-on-reboot-free-to-avoid-spurious-noises.patch