From 7c8d206f219fe52966d970f791246a542718e5ba Mon Sep 17 00:00:00 2001 From: Paul Parsons Date: Wed, 7 Mar 2012 14:13:41 +0000 Subject: [PATCH] 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 Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/maps/pcmciamtd.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) 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); } -- 2.30.2