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authorPaul Parsons <lost.distance@yahoo.com>2012-03-07 18:13:41 +0400
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-03-27 03:52:56 +0400
commit7c8d206f219fe52966d970f791246a542718e5ba (patch)
tree1b9c6e0630aed4df9efb911fccd276c978dd1b23
parent5fbabf3f45a15c2b39170980cee01368138f4d79 (diff)
downloadlinux-7c8d206f219fe52966d970f791246a542718e5ba.tar.xz
mtd: maps: pcmciamtd: 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 pcmciamtd_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>
-rw-r--r--drivers/mtd/maps/pcmciamtd.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/mtd/maps/pcmciamtd.c b/drivers/mtd/maps/pcmciamtd.c
index e8e9fec23553..7d5cf369f0ad 100644
--- a/drivers/mtd/maps/pcmciamtd.c
+++ b/drivers/mtd/maps/pcmciamtd.c
@@ -295,13 +295,24 @@ static void pcmcia_copy_to(struct map_info *map, unsigned long to, const void *f
}
+static DEFINE_SPINLOCK(pcmcia_vpp_lock);
+static int pcmcia_vpp_refcnt;
static void pcmciamtd_set_vpp(struct map_info *map, int on)
{
struct pcmciamtd_dev *dev = (struct pcmciamtd_dev *)map->map_priv_1;
struct pcmcia_device *link = dev->p_dev;
+ unsigned long flags;
pr_debug("dev = %p on = %d vpp = %d\n\n", dev, on, dev->vpp);
- pcmcia_fixup_vpp(link, on ? dev->vpp : 0);
+ spin_lock_irqsave(&pcmcia_vpp_lock, flags);
+ if (on) {
+ if (++pcmcia_vpp_refcnt == 1) /* first nested 'on' */
+ pcmcia_fixup_vpp(link, dev->vpp);
+ } else {
+ if (--pcmcia_vpp_refcnt == 0) /* last nested 'off' */
+ pcmcia_fixup_vpp(link, 0);
+ }
+ spin_unlock_irqrestore(&pcmcia_vpp_lock, flags);
}