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authorPaul Parsons <lost.distance@yahoo.com>2012-03-07 18:14:31 +0400
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-03-27 03:53:02 +0400
commitee478af8b675908b217198a75cf759d422a81ccb (patch)
tree3f9b3bdb6967607cf7e13579469f0ceaeb0e3bfe /drivers/mtd
parent7c8d206f219fe52966d970f791246a542718e5ba (diff)
downloadlinux-ee478af8b675908b217198a75cf759d422a81ccb.tar.xz
mtd: maps: sa1100-flash: Add reference counter to set_vpp()
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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/maps/sa1100-flash.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/mtd/maps/sa1100-flash.c b/drivers/mtd/maps/sa1100-flash.c
index cbc3b7867910..1eaf7b6c35e5 100644
--- a/drivers/mtd/maps/sa1100-flash.c
+++ b/drivers/mtd/maps/sa1100-flash.c
@@ -36,10 +36,22 @@ struct sa_info {
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)
{
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)