Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 28 insertions, 8 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index d915d0345fa1..72c0fe098a27 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -93,13 +93,23 @@ typedef struct pm_message {
  *      been registered) to recover from the race condition.
  *      This method is executed for all kinds of suspend transitions and is
  *      followed by one of the suspend callbacks: @suspend(), @freeze(), or
- *      @poweroff().  The PM core executes subsystem-level @prepare() for all
- *      devices before starting to invoke suspend callbacks for any of them, so
- *      generally devices may be assumed to be functional or to respond to
- *      runtime resume requests while @prepare() is being executed.  However,
- *      device drivers may NOT assume anything about the availability of user
- *      space at that time and it is NOT valid to request firmware from within
- *      @prepare() (it's too late to do that).  It also is NOT valid to allocate
+ *      @poweroff().  If the transition is a suspend to memory or standby (that
+ *      is, not related to hibernation), the return value of @prepare() may be
+ *      used to indicate to the PM core to leave the device in runtime suspend
+ *      if applicable.  Namely, if @prepare() returns a positive number, the PM
+ *      core will understand that as a declaration that the device appears to be
+ *      runtime-suspended and it may be left in that state during the entire
+ *      transition and during the subsequent resume if all of its descendants
+ *      are left in runtime suspend too.  If that happens, @complete() will be
+ *      executed directly after @prepare() and it must ensure the proper
+ *      functioning of the device after the system resume.
+ *      The PM core executes subsystem-level @prepare() for all devices before
+ *      starting to invoke suspend callbacks for any of them, so generally
+ *      devices may be assumed to be functional or to respond to runtime resume
+ *      requests while @prepare() is being executed.  However, device drivers
+ *      may NOT assume anything about the availability of user space at that
+ *      time and it is NOT valid to request firmware from within @prepare()
+ *      (it's too late to do that).  It also is NOT valid to allocate
  *      substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
  *      [To work around these limitations, drivers may register suspend and
  *      hibernation notifiers to be executed before the freezing of tasks.]
@@ -112,7 +122,16 @@ typedef struct pm_message {
  *      of the other devices that the PM core has unsuccessfully attempted to
  *      suspend earlier).
  *      The PM core executes subsystem-level @complete() after it has executed
- *      the appropriate resume callbacks for all devices.
+ *      the appropriate resume callbacks for all devices.  If the corresponding
+ *      @prepare() at the beginning of the suspend transition returned a
+ *      positive number and the device was left in runtime suspend (without
+ *      executing any suspend and resume callbacks for it), @complete() will be
+ *      the only callback executed for the device during resume.  In that case,
+ *      @complete() must be prepared to do whatever is necessary to ensure the
+ *      proper functioning of the device after the system resume.  To this end,
+ *      @complete() can check the power.direct_complete flag of the device to
+ *      learn whether (unset) or not (set) the previous suspend and resume
+ *      callbacks have been executed for it.
  *
  * @suspend: Executed before putting the system into a sleep state in which the
  *      contents of main memory are preserved.  The exact action to perform
@@ -546,6 +565,7 @@ struct dev_pm_info {
         bool                    is_late_suspended:1;
         bool                    ignore_children:1;
         bool                    early_init:1;   /* Owned by the PM core */
+        bool                    direct_complete:1;      /* Owned by the PM core */
         spinlock_t              lock;
 #ifdef CONFIG_PM_SLEEP
         struct list_head        entry;