When a machine is booted with nomodeset option, i915 driver skips the
whole initialization.  Meanwhile, HD-audio tries to bind wth i915 just
by request_symbol() without knowing that the initialization was
skipped, and eventually it hits WARN_ON() in i915_request_power_well()
and i915_release_power_well() wrongly but still continues probing,
even though it doesn't work at all.

In this patch, both functions are changed to return an error in case
of uninitialized state instead of WARN_ON(), so that HD-audio driver
can give up HDMI controller initialization at the right time.
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> [3.15]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Use dev_err() and co for messages from HD-audio controller and codec
drivers.  The codec drivers are mostly bound with codec objects, so
some helper macros, codec_err(), codec_info(), etc, are provided.
They merely wrap the corresponding dev_xxx().

There are a few places still calling snd_printk() and its variants
as they are called without the codec or device context.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

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: NWang Xingchao <xingchao.wang@linux.intel.com>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NLiam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: NDavid Henningsson <david.henningsson@canonical.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>