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authorPaul Parsons <lost.distance@yahoo.com>2012-03-07 14:12:50 +0000
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-03-27 00:52:49 +0100
commit5fbabf3f45a15c2b39170980cee01368138f4d79 (patch)
tree486eea6db78490042d4f6d0f6eb7bd8e834e2598
parent876fe76d793d03077eb61ba3afab4a383f46c554 (diff)
downloadop-kernel-dev-5fbabf3f45a15c2b39170980cee01368138f4d79.zip
op-kernel-dev-5fbabf3f45a15c2b39170980cee01368138f4d79.tar.gz
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>
-rw-r--r--drivers/mtd/maps/l440gx.c14
1 files changed, 9 insertions, 5 deletions
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 @@ static struct mtd_info *mymtd;
/* 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 = {
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