fsi: master-gpio: Add locking during break and link enable

Currently, we perform GPIO accesses in fsi_master_gpio_break and
fsi_master_link_enable, without holding cmd_lock. This change adds the
appropriate locking.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Christopher Bostic <clbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index ae26187685080563b78f5a16b92baba587a5a89b..a6d602e89c11201862fc9926e687ff3e400128e5 100644 (file)
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -461,12 +461,14 @@ static int fsi_master_gpio_term(struct fsi_master *_master,
 static int fsi_master_gpio_break(struct fsi_master *_master, int link)
 {
        struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
+       unsigned long flags;
 
        if (link != 0)
                return -ENODEV;
 
        trace_fsi_master_gpio_break(master);
 
+       spin_lock_irqsave(&master->cmd_lock, flags);
        set_sda_output(master, 1);
        sda_out(master, 1);
        clock_toggle(master, FSI_PRE_BREAK_CLOCKS);
@@ -475,6 +477,7 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link)
        echo_delay(master);
        sda_out(master, 1);
        clock_toggle(master, FSI_POST_BREAK_CLOCKS);
+       spin_unlock_irqrestore(&master->cmd_lock, flags);
 
        /* Wait for logic reset to take effect */
        udelay(200);
@@ -497,10 +500,14 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master)
 static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link)
 {
        struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
+       unsigned long flags;
 
        if (link != 0)
                return -ENODEV;
+
+       spin_lock_irqsave(&master->cmd_lock, flags);
        gpiod_set_value(master->gpio_enable, 1);
+       spin_unlock_irqrestore(&master->cmd_lock, flags);
 
        return 0;
 }