linux/sound
Ville Syrjälä 668e3b014a drm/i915: Fix runtime PM for LPE audio
Not calling pm_runtime_enable() means that runtime PM can't be
enabled at all via sysfs. So we definitely need to call it
from somewhere.

Calling it from the driver seems like a bad idea because it
would have to be paired with a pm_runtime_disable() at driver
unload time, otherwise the core gets upset. Also if there's
no LPE audio driver loaded then we couldn't runtime suspend
i915 either.

So it looks like a better plan is to call it from i915 when
we register the platform device. That seems to match how
pci generally does things. I cargo culted the
pm_runtime_forbid() and pm_runtime_set_active() calls from
pci as well.

The exposed runtime PM API is massive an thorougly misleading, so
I don't actually know if this is how you're supposed to use the API
or not. But it seems to work. I can now runtime suspend i915 again
with or without the LPE audio driver loaded, and reloading the
LPE audio driver also seems to work.

Note that powertop won't auto-tune runtime PM for platform devices,
which is a little annoying. So I'm not sure that leaving runtime
PM in "on" mode by default is the best choice here. But I've left
it like that for now at least.

Also remove the comment about there not being much benefit from
LPE audio runtime PM. Not allowing runtime PM blocks i915 runtime
PM, which will also block s0ix, and that could have a measurable
impact on power consumption.

Cc: stable@vger.kernel.org
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Fixes: 0b6b524f39 ("ALSA: x86: Don't enable runtime PM as default")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170427160231.13337-2-ville.syrjala@linux.intel.com
Reviewed-by: Takashi Iwai <tiwai@suse.de>
(cherry picked from commit 183c00350c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2017-05-15 14:44:11 +03:00
..
aoa
arm
atmel
core Merge branch 'for-linus' into for-next 2017-04-14 09:01:04 +02:00
drivers Annotation of module parameters that specify device settings 2017-05-10 19:13:03 -07:00
firewire ALSA: fireface: obsolete usage of ktime_set() for zero assignment 2017-04-20 15:00:54 +02:00
hda ALSA: hda: Fix cpu lockup when stopping the cmd dmas 2017-05-10 08:47:17 +02:00
i2c
isa Annotation of module parameters that specify device settings 2017-05-10 19:13:03 -07:00
mips ALSA: mips: avoid potential uninitialized variable use 2017-01-16 14:33:42 +01:00
oss Annotate hardware config module parameters in sound/oss/ 2017-04-20 12:02:32 +01:00
parisc
pci sound fixes for 4.12-rc1 2017-05-12 12:10:38 -07:00
pcmcia lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
ppc scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
sh
soc scripts/spelling.txt: add regsiter -> register spelling mistake 2017-05-08 17:15:13 -07:00
sparc
spi
synth ALSA: emux: stop if copy_from_user() fails 2017-03-31 16:23:52 +02:00
usb ALSA: usb-audio: replace /proc/bus/usb by /dev/bus/usb 2017-04-17 10:23:55 +02:00
x86 drm/i915: Fix runtime PM for LPE audio 2017-05-15 14:44:11 +03:00
Kconfig sound: Disable the build of OSS drivers 2017-05-12 09:57:20 +02:00
Makefile ALSA: add Intel HDMI LPE audio driver for BYT/CHT-T 2017-01-25 14:23:46 +01:00
ac97_bus.c
last.c
sound_core.c