vcs.maemo.org Git - kernel-power/blob - kernel-power-2.6.28/debian/patches/0002-mtd-change-struct-flchip_shared-spinlock-locking-int.diff

   1 From 2ccd3ea4bd9e62a348023bbf98988d01b6b5d7db Mon Sep 17 00:00:00 2001
   2 From: Stefani Seibold <stefani@seibold.net>
   3 Date: Thu, 5 Aug 2010 09:19:26 +0200
   4 Subject: [PATCH 2/2] mtd: change struct flchip_shared spinlock locking into mutex
   5
   6 This patch prevent to schedule while atomic by changing the
   7 flchip_shared spinlock into a mutex. This should be save since no atomic
   8 path will use this lock.
   9
  10 It was suggested by Arnd Bergmann and Vasiliy Kulikov.
  11
  12 Signed-off-by: Stefani Seibold <stefani@seibold.net>
  13 Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
  14 Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
  15 ---
  16  drivers/mtd/chips/cfi_cmdset_0001.c |   20 ++++++++++----------
  17  include/linux/mtd/flashchip.h       |    2 +-
  18  2 files changed, 11 insertions(+), 11 deletions(-)
  19
  20 diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
  21 index c9c3517..892a862 100644
  22 --- a/drivers/mtd/chips/cfi_cmdset_0001.c
  23 +++ b/drivers/mtd/chips/cfi_cmdset_0001.c
  24 @@ -687,7 +687,7 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd,
  25                 chip = &newcfi->chips[0];
  26                 for (i = 0; i < cfi->numchips; i++) {
  27                         shared[i].writing = shared[i].erasing = NULL;
  28 -                       spin_lock_init(&shared[i].lock);
  29 +                       mutex_init(&shared[i].lock);
  30                         for (j = 0; j < numparts; j++) {
  31                                 *chip = cfi->chips[i];
  32                                 chip->start += j << partshift;
  33 @@ -856,7 +856,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
  34                  */
  35                 struct flchip_shared *shared = chip->priv;
  36                 struct flchip *contender;
  37 -               spin_lock(&shared->lock);
  38 +               mutex_lock(&shared->lock);
  39                 contender = shared->writing;
  40                 if (contender && contender != chip) {
  41                         /*
  42 @@ -869,7 +869,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
  43                          * get_chip returns success we're clear to go ahead.
  44                          */
  45                         ret = mutex_trylock(&contender->mutex);
  46 -                       spin_unlock(&shared->lock);
  47 +                       mutex_unlock(&shared->lock);
  48                         if (!ret)
  49                                 goto retry;
  50                         mutex_unlock(&chip->mutex);
  51 @@ -884,7 +884,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
  52                                 mutex_unlock(&contender->mutex);
  53                                 return ret;
  54                         }
  55 -                       spin_lock(&shared->lock);
  56 +                       mutex_lock(&shared->lock);
  57
  58                         /* We should not own chip if it is already
  59                          * in FL_SYNCING state. Put contender and retry. */
  60 @@ -900,7 +900,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
  61                  * on this chip. Sleep. */
  62                 if (mode == FL_ERASING && shared->erasing
  63                     && shared->erasing->oldstate == FL_ERASING) {
  64 -                       spin_unlock(&shared->lock);
  65 +                       mutex_unlock(&shared->lock);
  66                         set_current_state(TASK_UNINTERRUPTIBLE);
  67                         add_wait_queue(&chip->wq, &wait);
  68                         mutex_unlock(&chip->mutex);
  69 @@ -914,7 +914,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr
  70                 shared->writing = chip;
  71                 if (mode == FL_ERASING)
  72                         shared->erasing = chip;
  73 -               spin_unlock(&shared->lock);
  74 +               mutex_unlock(&shared->lock);
  75         }
  76         ret = chip_ready(map, chip, adr, mode);
  77         if (ret == -EAGAIN)
  78 @@ -929,7 +929,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
  79
  80         if (chip->priv) {
  81                 struct flchip_shared *shared = chip->priv;
  82 -               spin_lock(&shared->lock);
  83 +               mutex_lock(&shared->lock);
  84                 if (shared->writing == chip && chip->oldstate == FL_READY) {
  85                         /* We own the ability to write, but we're done */
  86                         shared->writing = shared->erasing;
  87 @@ -937,7 +937,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
  88                                 /* give back ownership to who we loaned it from */
  89                                 struct flchip *loaner = shared->writing;
  90                                 mutex_lock(&loaner->mutex);
  91 -                               spin_unlock(&shared->lock);
  92 +                               mutex_unlock(&shared->lock);
  93                                 mutex_unlock(&chip->mutex);
  94                                 put_chip(map, loaner, loaner->start);
  95                                 mutex_lock(&chip->mutex);
  96 @@ -955,11 +955,11 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
  97                          * Don't let the switch below mess things up since
  98                          * we don't have ownership to resume anything.
  99                          */
 100 -                       spin_unlock(&shared->lock);
 101 +                       mutex_unlock(&shared->lock);
 102                         wake_up(&chip->wq);
 103                         return;
 104                 }
 105 -               spin_unlock(&shared->lock);
 106 +               mutex_unlock(&shared->lock);
 107         }
 108
 109         switch(chip->oldstate) {
 110 diff --git a/include/linux/mtd/flashchip.h b/include/linux/mtd/flashchip.h
 111 index bfc2f1a..fa6db00 100644
 112 --- a/include/linux/mtd/flashchip.h
 113 +++ b/include/linux/mtd/flashchip.h
 114 @@ -83,7 +83,7 @@ struct flchip {
 115  /* This is used to handle contention on write/erase operations
 116     between partitions of the same physical chip. */
 117  struct flchip_shared {
 118 -       spinlock_t lock;
 119 +       struct mutex lock;
 120         struct flchip *writing;
 121         struct flchip *erasing;
 122  };
 123 --
 124 1.7.3.4
 125