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    Subject[07/34] arm/imx/gpio: add spinlock protection
    2.6.32-stable review patch.  If anyone has any objections, please let us know.

    ------------------

    From: Baruch Siach <baruch@tkos.co.il>

    commit 14cb0deb66fcfca8fdbef75da8c84b5405a8c767 upstream.

    The GPIO registers need protection from concurrent access for operations that
    are not atomic.

    Cc: Juergen Beisert <j.beisert@pengutronix.de>
    Cc: Daniel Mack <daniel@caiaq.de>
    Reported-by: rpkamiak@rockwellcollins.com
    Signed-off-by: Baruch Siach <baruch@tkos.co.il>
    Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.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
    @@ -223,13 +223,16 @@ 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)
    @@ -238,9 +241,12 @@ 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)
    @@ -294,6 +300,8 @@ 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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