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mtd: maps: sa1100-flash: Add reference counter to set_vpp()

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This patch is part of a set which fixes unnecessary flash erase and write errors
resulting from the MTD CFI driver turning off vpp while an erase is in progress.
This patch allows sa1100_set_vpp() calls to be nested by adding a reference
counter.

Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Paul Parsons 2012-03-07 14:14:31 +00:00 committed by David Woodhouse
parent 7c8d206f21
commit ee478af8b6
1 changed files with 13 additions and 1 deletions
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14
drivers/mtd/maps/sa1100-flash.c
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@ -36,10 +36,22 @@ struct sa_info {
struct sa_subdev_info subdev[0]; struct sa_subdev_info subdev[0];
}; };
static DEFINE_SPINLOCK(sa1100_vpp_lock);
static int sa1100_vpp_refcnt;
static void sa1100_set_vpp(struct map_info *map, int on) static void sa1100_set_vpp(struct map_info *map, int on)
{ {
struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map); struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
subdev->plat->set_vpp(on); unsigned long flags;
spin_lock_irqsave(&sa1100_vpp_lock, flags);
if (on) {
if (++sa1100_vpp_refcnt == 1) /* first nested 'on' */
subdev->plat->set_vpp(1);
} else {
if (--sa1100_vpp_refcnt == 0) /* last nested 'off' */
subdev->plat->set_vpp(0);
}
spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
} }
static void sa1100_destroy_subdev(struct sa_subdev_info *subdev) static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)