Patch "ALSA: hda - Revert power_save option default value" has been added to the 4.9-stable tree

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

ALSA: hda - Revert power_save option default value

to the 4.9-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-revert-power_save-option-default-value.patch
and it can be found in the queue-4.9 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, 12 Mar 2018 13:55:48 +0100
Subject: ALSA: hda - Revert power_save option default value

From: Takashi Iwai <[email protected]>

commit 40088dc4e1ead7df31728c73f5b51d71da18831d upstream.

With the commit 1ba8f9d30817 ("ALSA: hda: Add a power_save blacklist"), we changed the default value of power_save option to -1 for processing the power-save blacklist.
Unfortunately, this seems breaking user-space applications that actually read the power_save parameter value via sysfs and judge / adjust the power-saving status. They see the value -1 as if the power-save is turned off, although the actual value is taken from CONFIG_SND_HDA_POWER_SAVE_DEFAULT and it can be a positive.

So, overall, passing -1 there was no good idea. Let's partially revert it -- at least for power_save option default value is restored again to CONFIG_SND_HDA_POWER_SAVE_DEFAULT. Meanwhile, in this patch, we keep the blacklist behavior and make is adjustable via the new option, pm_blacklist.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199073

---
 sound/pci/hda/hda_intel.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

@@ -180,11 +180,15 @@ static const struct kernel_param_ops par
 };
 #define param_check_xint param_check_int
 
-static int power_save = -1;
+static int power_save = CONFIG_SND_HDA_POWER_SAVE_DEFAULT;
 module_param(power_save, xint, 0644);
 MODULE_PARM_DESC(power_save, "Automatic power-saving timeout "
 		 "(in second, 0 = disable).");
 
+static bool pm_blacklist = true;
+module_param(pm_blacklist, bool, 0644);
+MODULE_PARM_DESC(pm_blacklist, "Enable power-management blacklist");
+
 /* reset the HD-audio controller in power save mode.
  * this may give more power-saving, but will take longer time to
  * wake up.

@@ -2153,10 +2157,9 @@ static int azx_probe_continue(struct azx
 
 	val = power_save;
 #ifdef CONFIG_PM
-	if (val == -1) {
+	if (pm_blacklist) {
 		const struct snd_pci_quirk *q;
 
-		val = CONFIG_SND_HDA_POWER_SAVE_DEFAULT;
 		q = snd_pci_quirk_lookup(chip->pci, power_save_blacklist);
 		if (q && val) {
 			dev_info(chip->card->dev, "device %04x:%04x is on the power_save blacklist, forcing power_save to 0\n",

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

queue-4.9/alsa-hda-add-geminilake-id-to-skl_plus.patch queue-4.9/alsa-firewire-digi00x-handle-all-midi-messages-on-streaming-packets.patch queue-4.9/alsa-firewire-digi00x-add-support-for-console-models-of-digi00x-series.patch queue-4.9/alsa-pcm-fix-uaf-in-snd_pcm_oss_get_formats.patch queue-4.9/alsa-seq-fix-possible-uaf-in-snd_seq_check_queue.patch queue-4.9/alsa-hda-revert-power_save-option-default-value.patch queue-4.9/alsa-seq-clear-client-entry-before-deleting-else-at-closing.patch queue-4.9/alsa-firewire-lib-add-a-quirk-of-packet-without-valid-eoh-in-cip-format.patch