Merge tag 'sound-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "This time it's a relatively calm update batch, but the amount isn't
  too small in the end.  Here we go over some highlights:

  ALSA core:
   - One major change is the support of nonatomic PCM operations.  This
     allows the trigger and other callbacks to call schedule(), which
     would be useful for mailbox type communications.  Already some
     drivers (Digigram ones) have been converted to use together with
     threaded irqs as an example.
   - Improvement / fixes of DSD PCM format support

  HD-audio:
   - Large volume of rewrites are found in Realtek codec driver for
     converting Dell and HP quirks to generic forms.
   - Inverted dmic code cleanup from David.
   - Realtek COEF access has been optimized.
   - Now HD-audio jack infrastructure allows multiple callbacks, which
     fixes / simplifies the jack-dependent power controls on STAC/IDT
     and VIA codecs.
   - Many additional device-specific fixups as usual
   - A few deadcode cleanups, CA0132 code cleanup, etc.

  ASoC:
   - More componentization work from Lars-Peter, this time mainly
     cleaning up the suspend and bias level transition callbacks.
   - Real system support for the Intel drivers and a bunch of fixes and
     enhancements for the associated CODEC drivers, this is going to
     need a lot quirks over time due to the lack of any firmware
     description of the boards.
   - Jack detect support for simple card from Dylan Reid.
   - A bunch of small fixes and enhancements for the Freescale drivers.
   - New drivers for Analog Devices SSM4567, Cirrus Logic CS35L32,
     Everest Semiconductor ES8328 and Freescale cards using the ASRC in
     newer i.MX processors.
   - A few simple-card fixes, mostly cleanups but also a fix for
     interaction between GPIO 0 and simple-card.

  Misc:
   - Virtuoso / Oxygen updates by Clemens
   - USB-audio: Yamaha MOTIF XF MIDI port name fixes
   - Conversion of kernel messages to standard dev_*() in ctxfi driver"

* tag 'sound-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (251 commits)
  ASoC: mc13783: Ensure we only try to dereference valid of_nodes
  ASoC: rockchip-i2s: fix infinite loop in rockchip_snd_txctrl
  ALSA: hda - Add dock port support to Thinkpad L440 (71aa:501e)
  ALSA: Allow pass NULL dev for snd_pci_quirk_lookup()
  ASoC: imx-es8328: Fix of_node_put() call with uninitialized object
  ASoC: soc-pcm: fix sig_bits determination in soc_pcm_apply_msb()
  ASoC: simple-card: Initialize headphone and mic GPIO numbers
  ASoC: imx-es8328: Fix missing return code in imx_es8328_probe()
  ALSA: hda - Add dock support for Thinkpad T440 (17aa:2212)
  ALSA: usb: caiaq: check for cdev->n_streams > 1
  ASoC: 88pm860x-codec: Fix possibly missing string termination
  ASoC: core: fix use after free in snd_soc_remove_platform()
  ASoC: soc-dapm: fix use after free
  ALSA: hda - Make the inv dmic handling for Realtek use generic parser
  ALSA: hda - Add Inverted Internal mic for Samsung Ativ book 9 (NP900X3G)
  ALSA: hda - Add inverted internal mic for Asus Aspire 4830T
  ASoC: Intel: byt-rt5640: fix coccinelle warnings
  ASoC: fsl_esai doc: Add "fsl,vf610-esai" as compatible string
  ASoC: da732x: Remove unnecessary KERN_ERR in pr_err()
  ASoC: simple-card: Fix detect gpio documentation.
  ...

1 files changed, 23 insertions, 5 deletions

diff --git a/Documentation/DocBook/writing-an-alsa-driver.tmpl b/Documentation/DocBook/writing-an-alsa-driver.tmpl
index 6f639d9530b5..784793df81ed 100644
--- a/Documentation/DocBook/writing-an-alsa-driver.tmpl
+++ b/Documentation/DocBook/writing-an-alsa-driver.tmpl
@@ -2742,7 +2742,9 @@ struct _snd_pcm_runtime {
 
         <para>
           Another note is that this callback is non-atomic
-        (schedulable). This is important, because the
+        (schedulable) as default, i.e. when no
+	<structfield>nonatomic</structfield> flag set.
+	This is important, because the
         <structfield>trigger</structfield> callback 
         is atomic (non-schedulable). That is, mutexes or any
         schedule-related functions are not available in
@@ -2900,8 +2902,9 @@ struct _snd_pcm_runtime {
         </para>
 
         <para>
-          As mentioned, this callback is atomic.  You cannot call
-	  functions which may sleep.
+          As mentioned, this callback is atomic as default unless
+	  <structfield>nonatomic</structfield> flag set, and
+	  you cannot call functions which may sleep.
 	  The trigger callback should be as minimal as possible,
 	  just really triggering the DMA.  The other stuff should be
 	  initialized hw_params and prepare callbacks properly
@@ -2936,7 +2939,7 @@ struct _snd_pcm_runtime {
         </para>
 
         <para>
-          This callback is also atomic.
+          This callback is also atomic as default.
         </para>
       </section>
 
@@ -2972,7 +2975,7 @@ struct _snd_pcm_runtime {
 	is useful only for such a purpose.
 	</para>
 	<para>
-	  This callback is atomic.
+	  This callback is atomic as default.
 	</para>
       </section>
 
@@ -3175,6 +3178,21 @@ struct _snd_pcm_runtime {
       called with local interrupts disabled.
       </para>
 
+      <para>
+      The recent changes in PCM core code, however, allow all PCM
+      operations to be non-atomic.  This assumes that the all caller
+      sides are in non-atomic contexts.  For example, the function
+      <function>snd_pcm_period_elapsed()</function> is called
+      typically from the interrupt handler.  But, if you set up the
+      driver to use a threaded interrupt handler, this call can be in
+      non-atomic context, too.  In such a case, you can set
+      <structfield>nonatomic</structfield> filed of
+      <structname>snd_pcm</structname> object after creating it.
+      When this flag is set, mutex and rwsem are used internally in
+      the PCM core instead of spin and rwlocks, so that you can call
+      all PCM functions safely in a non-atomic context.
+      </para>
+
     </section>
     <section id="pcm-interface-constraints">
       <title>Constraints</title>