Add a bunch of cycle_kernel_lock() calls

All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

drivers/char/pc8736x_gpio.c

@@ -20,6 +20,7 @@
 #include <linux/mutex.h>
 #include <linux/nsc_gpio.h>
 #include <linux/platform_device.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
 #define DEVNAME "pc8736x_gpio"
@@ -212,12 +213,12 @@ static struct nsc_gpio_ops pc8736x_gpio_ops = {
 	.gpio_current	= pc8736x_gpio_current
 };
 
-/* No BKL needed here; no global resources accessed */
 static int pc8736x_gpio_open(struct inode *inode, struct file *file)
 {
 	unsigned m = iminor(inode);
 	file->private_data = &pc8736x_gpio_ops;
 
+	cycle_kernel_lock();
 	dev_dbg(&pdev->dev, "open %d\n", m);
 
 	if (m >= PC8736X_GPIO_CT)