mtd: maps: l440gx: 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 l440gx_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>
diff --git a/drivers/mtd/maps/l440gx.c b/drivers/mtd/maps/l440gx.c
index dd0360b..74bd98e 100644
--- a/drivers/mtd/maps/l440gx.c
+++ b/drivers/mtd/maps/l440gx.c
@@ -27,17 +27,21 @@
/* Is this really the vpp port? */
+static DEFINE_SPINLOCK(l440gx_vpp_lock);
+static int l440gx_vpp_refcnt;
static void l440gx_set_vpp(struct map_info *map, int vpp)
{
- unsigned long l;
+ unsigned long flags;
- l = inl(VPP_PORT);
+ spin_lock_irqsave(&l440gx_vpp_lock, flags);
if (vpp) {
- l |= 1;
+ if (++l440gx_vpp_refcnt == 1) /* first nested 'on' */
+ outl(inl(VPP_PORT) | 1, VPP_PORT);
} else {
- l &= ~1;
+ if (--l440gx_vpp_refcnt == 0) /* last nested 'off' */
+ outl(inl(VPP_PORT) & ~1, VPP_PORT);
}
- outl(l, VPP_PORT);
+ spin_unlock_irqrestore(&l440gx_vpp_lock, flags);
}
static struct map_info l440gx_map = {