From: Glenn Langedock <redacted>

Fix race condition when changing the direction (in/out) of the GPIO pin.
The read-modify-write sequence (as coded in the driver) isn't atomic and
requires synchronization (spinlock).

Signed-off-by: Glenn Langedock <redacted>
Signed-off-by: Michal Simek <redacted>
Signed-off-by: Srinivas Neeli <redacted>
---
 drivers/gpio/gpio-zynq.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
index 05ba16fffdad..9c8b8a397a26 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c

@@ -10,6 +10,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>

@@ -116,6 +117,7 @@ struct gpio_regs {
  * @irq:       interrupt for the GPIO device
  * @p_data:    pointer to platform data
  * @context:   context registers
+ * @dirlock:   lock used for direction in/out synchronization
  */
 struct zynq_gpio {
        struct gpio_chip chip;

@@ -124,6 +126,7 @@ struct zynq_gpio {
        int irq;
        const struct zynq_platform_data *p_data;
        struct gpio_regs context;
+       spinlock_t dirlock; /*lock used for direction in/out synchronization */