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, 22 insertions, 4 deletions

diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
index 5af65719b95..a9b1cd16c84 100644
--- a/drivers/gpio/gpio-sch.c
+++ b/drivers/gpio/gpio-sch.c
@@ -97,8 +97,6 @@ static int sch_gpio_core_direction_out(struct gpio_chip *gc,
 	u8 curr_dirs;
 	unsigned short offset, bit;
 
-	sch_gpio_core_set(gc, gpio_num, val);
-
 	spin_lock(&gpio_lock);
 
 	offset = CGIO + gpio_num / 8;
@@ -109,6 +107,17 @@ static int sch_gpio_core_direction_out(struct gpio_chip *gc,
 		outb(curr_dirs & ~(1 << bit), gpio_ba + offset);
 
 	spin_unlock(&gpio_lock);
+
+	/*
+	 * according to the datasheet, writing to the level register has no
+	 * effect when GPIO is programmed as input.
+	 * Actually the the level register is read-only when configured as input.
+	 * Thus presetting the output level before switching to output is _NOT_ possible.
+	 * Hence we set the level after configuring the GPIO as output.
+	 * But we cannot prevent a short low pulse if direction is set to high
+	 * and an external pull-up is connected.
+	 */
+	sch_gpio_core_set(gc, gpio_num, val);
 	return 0;
 }
 
@@ -178,8 +187,6 @@ static int sch_gpio_resume_direction_out(struct gpio_chip *gc,
 	u8 curr_dirs;
 	unsigned short offset, bit;
 
-	sch_gpio_resume_set(gc, gpio_num, val);
-
 	offset = RGIO + gpio_num / 8;
 	bit = gpio_num % 8;
 
@@ -190,6 +197,17 @@ static int sch_gpio_resume_direction_out(struct gpio_chip *gc,
 		outb(curr_dirs & ~(1 << bit), gpio_ba + offset);
 
 	spin_unlock(&gpio_lock);
+
+	/*
+	* according to the datasheet, writing to the level register has no
+	* effect when GPIO is programmed as input.
+	* Actually the the level register is read-only when configured as input.
+	* Thus presetting the output level before switching to output is _NOT_ possible.
+	* Hence we set the level after configuring the GPIO as output.
+	* But we cannot prevent a short low pulse if direction is set to high
+	* and an external pull-up is connected.
+	*/
+	sch_gpio_resume_set(gc, gpio_num, val);
 	return 0;
 }