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 <j...@ozlabs.org>
Reviewed-by: Joel Stanley <j...@jms.id.au>
Reviewed-by: Christopher Bostic <clbos...@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-master-gpio.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index ae26187..a6d602e 100644
--- 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;
 }
-- 
2.7.4

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