mtd: change struct flchip_shared spinlock locking into mutex

This patch prevent to schedule while atomic by changing the
flchip_shared spinlock into a mutex. This should be save since no atomic
path will use this lock.

It was suggested by Arnd Bergmann and Vasiliy Kulikov.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 10 insertions, 10 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 2fadb0239ba3..97d5546f9ea4 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -720,7 +720,7 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd,
                 chip = &newcfi->chips[0];
                 for (i = 0; i < cfi->numchips; i++) {
                         shared[i].writing = shared[i].erasing = NULL;
-                        spin_lock_init(&shared[i].lock);
+                        mutex_init(&shared[i].lock);
                         for (j = 0; j < numparts; j++) {
                                 *chip = cfi->chips[i];
                                 chip->start += j << partshift;
@@ -889,7 +889,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                  */
                 struct flchip_shared *shared = chip->priv;
                 struct flchip *contender;
-                spin_lock(&shared->lock);
+                mutex_lock(&shared->lock);
                 contender = shared->writing;
                 if (contender && contender != chip) {
                         /*
@@ -902,7 +902,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                          * get_chip returns success we're clear to go ahead.
                          */
                         ret = mutex_trylock(&contender->mutex);
-                        spin_unlock(&shared->lock);
+                        mutex_unlock(&shared->lock);
                         if (!ret)
                                 goto retry;
                         mutex_unlock(&chip->mutex);
@@ -917,7 +917,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                                 mutex_unlock(&contender->mutex);
                                 return ret;
                         }
-                        spin_lock(&shared->lock);
+                        mutex_lock(&shared->lock);
 
                         /* We should not own chip if it is already
                          * in FL_SYNCING state. Put contender and retry. */
@@ -933,7 +933,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                  * on this chip. Sleep. */
                 if (mode == FL_ERASING && shared->erasing
                     && shared->erasing->oldstate == FL_ERASING) {
-                        spin_unlock(&shared->lock);
+                        mutex_unlock(&shared->lock);
                         set_current_state(TASK_UNINTERRUPTIBLE);
                         add_wait_queue(&chip->wq, &wait);
                         mutex_unlock(&chip->mutex);
@@ -947,7 +947,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
                 shared->writing = chip;
                 if (mode == FL_ERASING)
                         shared->erasing = chip;
-                spin_unlock(&shared->lock);
+                mutex_unlock(&shared->lock);
         }
         ret = chip_ready(map, chip, adr, mode);
         if (ret == -EAGAIN)
@@ -962,7 +962,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
 
         if (chip->priv) {
                 struct flchip_shared *shared = chip->priv;
-                spin_lock(&shared->lock);
+                mutex_lock(&shared->lock);
                 if (shared->writing == chip && chip->oldstate == FL_READY) {
                         /* We own the ability to write, but we're done */
                         shared->writing = shared->erasing;
@@ -970,7 +970,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
                                 /* give back ownership to who we loaned it from */
                                 struct flchip *loaner = shared->writing;
                                 mutex_lock(&loaner->mutex);
-                                spin_unlock(&shared->lock);
+                                mutex_unlock(&shared->lock);
                                 mutex_unlock(&chip->mutex);
                                 put_chip(map, loaner, loaner->start);
                                 mutex_lock(&chip->mutex);
@@ -988,11 +988,11 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
                          * Don't let the switch below mess things up since
                          * we don't have ownership to resume anything.
                          */
-                        spin_unlock(&shared->lock);
+                        mutex_unlock(&shared->lock);
                         wake_up(&chip->wq);
                         return;
                 }
-                spin_unlock(&shared->lock);
+                mutex_unlock(&shared->lock);
         }
 
         switch(chip->oldstate) {