sony_pi: Remove the BKL from open and ioctl

The BKL is in this function because of the BKL pushdown (see commit
f8f2c79d594463427f7114cedb1555110d547d89)

It is not needed here because the mutex_lock sonypi_device.lock provides
the necessary locking.

sonypi_misc_ioctl can be converted to unlocked ioctls since it relies on
its own locking (the mutex sonypi_device.lock) and not the bkl

Document that llseek is not needed by explictly setting it to no_llseek

LKML-Reference: <[e-mail]>
Signed-off-by: John Kacur <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/char/sonypi.c

···
 #include <linux/err.h>
 #include <linux/kfifo.h>
 #include <linux/platform_device.h>
-#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
···
 
 static int sonypi_misc_open(struct inode *inode, struct file *file)
 {
-	lock_kernel();
 	mutex_lock(&sonypi_device.lock);
 	/* Flush input queue on first open */
 	if (!sonypi_device.open_count)
 		kfifo_reset(&sonypi_device.fifo);
 	sonypi_device.open_count++;
 	mutex_unlock(&sonypi_device.lock);
-	unlock_kernel();
+
 	return 0;
 }
 
···
 	return 0;
 }
 
-static int sonypi_misc_ioctl(struct inode *ip, struct file *fp,
+static long sonypi_misc_ioctl(struct file *fp,
 			     unsigned int cmd, unsigned long arg)
 {
-	int ret = 0;
+	long ret = 0;
 	void __user *argp = (void __user *)arg;
 	u8 val8;
 	u16 val16;
···
 	.open		= sonypi_misc_open,
 	.release	= sonypi_misc_release,
 	.fasync		= sonypi_misc_fasync,
-	.ioctl		= sonypi_misc_ioctl,
+	.unlocked_ioctl	= sonypi_misc_ioctl,
+	.llseek		= no_llseek,
 };
 
 static struct miscdevice sonypi_misc_device = {