[PATCH] ALSA: hda - Revert power_save option default value

[PATCH] ALSA: hda - Revert power_save option default value

[Takashi Iwai]

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
Fixes: 1ba8f9d30817 ("ALSA: hda: Add a power_save blacklist")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/pci/hda/hda_intel.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 96143df19b21..d5017adf9feb 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -181,11 +181,15 @@ static const struct kernel_param_ops param_ops_xint = {
 };
 #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.
@@ -2300,10 +2304,9 @@ static int azx_probe_continue(struct azx *chip)
 
 	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",
-- 
2.16.2

Re: [PATCH] ALSA: hda - Revert power_save option default value

[Hans de Goede]

Hi,

On 12-03-18 14:04, Takashi Iwai wrote:
> 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
> Fixes: 1ba8f9d30817 ("ALSA: hda: Add a power_save blacklist")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>

Thank you for taking care of this and not just reverting my patch.

Your fix looks good to me:

Acked-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans



> ---
>   sound/pci/hda/hda_intel.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index 96143df19b21..d5017adf9feb 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -181,11 +181,15 @@ static const struct kernel_param_ops param_ops_xint = {
>   };
>   #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.
> @@ -2300,10 +2304,9 @@ static int azx_probe_continue(struct azx *chip)
>   
>   	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",
>