ALSA: hda - Add power-welll support for haswell HDA
For Intel Haswell chip, HDA controller and codec have
power well dependency from GPU side. This patch added support
to request/release power well in audio driver. Power save
feature should be enabled to get runtime power saving.
There's deadlock when request_module(i915) in azx_probe.
It looks like:
device_lock(audio pci device) -> azx_probe -> module_request
(or symbol_request) -> modprobe (userspace) -> i915 init ->
drm_pci_init -> pci_register_driver -> bus_add_driver -> driver_attach ->
which in turn tries all locks on pci bus, and when it tries the one on the
audio device, it will deadlock.
This patch introduce a work to store remaining probe stuff, and let
request_module run in safe work context.
Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index 80a7d44..c5a872c 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -152,6 +152,16 @@
snd-hda-codec-hdmi.
This module is automatically loaded at probing.
+config SND_HDA_I915
+ bool "Build Display HD-audio controller/codec power well support for i915 cards"
+ depends on DRM_I915
+ help
+ Say Y here to include full HDMI and DisplayPort HD-audio controller/codec
+ power-well support for Intel Haswell graphics cards based on the i915 driver.
+
+ Note that this option must be enabled for Intel Haswell C+ stepping machines, otherwise
+ the GPU audio controller/codecs will not be initialized or damaged when exit from S3 mode.
+
config SND_HDA_CODEC_CIRRUS
bool "Build Cirrus Logic codec support"
default y