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Message-Id: <20100806183200.209512682@clark.site>
Date: Fri, 06 Aug 2010 11:30:23 -0700
From: Greg KH <gregkh@...e.de>
To: linux-kernel@...r.kernel.org, stable@...nel.org
Cc: stable-review@...nel.org, torvalds@...ux-foundation.org,
akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
Juergen Beisert <j.beisert@...gutronix.de>,
Daniel Mack <daniel@...aq.de>,
Baruch Siach <baruch@...s.co.il>,
Sascha Hauer <s.hauer@...gutronix.de>
Subject: [02/38] arm/imx/gpio: add spinlock protection
2.6.35-stable review patch. If anyone has any objections, please let us know.
------------------
From: Baruch Siach <baruch@...s.co.il>
commit 14cb0deb66fcfca8fdbef75da8c84b5405a8c767 upstream.
The GPIO registers need protection from concurrent access for operations that
are not atomic.
Cc: Juergen Beisert <j.beisert@...gutronix.de>
Cc: Daniel Mack <daniel@...aq.de>
Reported-by: rpkamiak@...kwellcollins.com
Signed-off-by: Baruch Siach <baruch@...s.co.il>
Signed-off-by: Sascha Hauer <s.hauer@...gutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
arch/arm/plat-mxc/gpio.c | 8 ++++++++
arch/arm/plat-mxc/include/mach/gpio.h | 1 +
2 files changed, 9 insertions(+)
--- a/arch/arm/plat-mxc/gpio.c
+++ b/arch/arm/plat-mxc/gpio.c
@@ -214,13 +214,16 @@ static void _set_gpio_direction(struct g
struct mxc_gpio_port *port =
container_of(chip, struct mxc_gpio_port, chip);
u32 l;
+ unsigned long flags;
+ spin_lock_irqsave(&port->lock, flags);
l = __raw_readl(port->base + GPIO_GDIR);
if (dir)
l |= 1 << offset;
else
l &= ~(1 << offset);
__raw_writel(l, port->base + GPIO_GDIR);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
@@ -229,9 +232,12 @@ static void mxc_gpio_set(struct gpio_chi
container_of(chip, struct mxc_gpio_port, chip);
void __iomem *reg = port->base + GPIO_DR;
u32 l;
+ unsigned long flags;
+ spin_lock_irqsave(&port->lock, flags);
l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
__raw_writel(l, reg);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
@@ -285,6 +291,8 @@ int __init mxc_gpio_init(struct mxc_gpio
port[i].chip.base = i * 32;
port[i].chip.ngpio = 32;
+ spin_lock_init(&port[i].lock);
+
/* its a serious configuration bug when it fails */
BUG_ON( gpiochip_add(&port[i].chip) < 0 );
--- a/arch/arm/plat-mxc/include/mach/gpio.h
+++ b/arch/arm/plat-mxc/include/mach/gpio.h
@@ -36,6 +36,7 @@ struct mxc_gpio_port {
int virtual_irq_start;
struct gpio_chip chip;
u32 both_edges;
+ spinlock_t lock;
};
int mxc_gpio_init(struct mxc_gpio_port*, int);
--
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