Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 831c70fc authored by Matthias Kaehlcke's avatar Matthias Kaehlcke Committed by Greg Kroah-Hartman
Browse files

USB: use mutex instead of semaphore in the USB gadget serial driver 



The USB gadget serial driver uses a semaphore as mutex. Use the
mutex API instead of the (binary) semaphore.

Signed-off-by: default avatarMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Acked-by: default avatarDavid Brownell <david-b@pacbell.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 64fb98fc

drivers/usb/gadget/serial.c

+13 −12
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/device.h>

#include <linux/tty.h>

#include <linux/tty_flip.h>

#include <linux/mutex.h>



#include <asm/byteorder.h>

#include <asm/io.h>
@@ -258,7 +259,7 @@ static const char *EP_IN_NAME; 
static const char *EP_OUT_NAME;

static const char *EP_NOTIFY_NAME;



static struct semaphore	gs_open_close_sem[GS_NUM_PORTS];

static struct mutex gs_open_close_lock[GS_NUM_PORTS];



static unsigned int read_q_size = GS_DEFAULT_READ_Q_SIZE;

static unsigned int write_q_size = GS_DEFAULT_WRITE_Q_SIZE;
@@ -595,7 +596,7 @@ static int __init gs_module_init(void) 
	tty_set_operations(gs_tty_driver, &gs_tty_ops);



	for (i=0; i < GS_NUM_PORTS; i++)

		sema_init(&gs_open_close_sem[i], 1);

		mutex_init(&gs_open_close_lock[i]);



	retval = tty_register_driver(gs_tty_driver);

	if (retval) {
@@ -635,7 +636,7 @@ static int gs_open(struct tty_struct *tty, struct file *file) 
	struct gs_port *port;

	struct gs_dev *dev;

	struct gs_buf *buf;

	struct semaphore *sem;

	struct mutex *mtx;

	int ret;



	port_num = tty->index;
@@ -656,10 +657,10 @@ static int gs_open(struct tty_struct *tty, struct file *file) 
		return -ENODEV;

	}



	sem = &gs_open_close_sem[port_num];

	if (down_interruptible(sem)) {

	mtx = &gs_open_close_lock[port_num];

	if (mutex_lock_interruptible(mtx)) {

		printk(KERN_ERR

		"gs_open: (%d,%p,%p) interrupted waiting for semaphore\n",

		"gs_open: (%d,%p,%p) interrupted waiting for mutex\n",

			port_num, tty, file);

		return -ERESTARTSYS;

	}
@@ -754,12 +755,12 @@ static int gs_open(struct tty_struct *tty, struct file *file) 


exit_unlock_port:

	spin_unlock_irqrestore(&port->port_lock, flags);

	up(sem);

	mutex_unlock(mtx);

	return ret;



exit_unlock_dev:

	spin_unlock_irqrestore(&dev->dev_lock, flags);

	up(sem);

	mutex_unlock(mtx);

	return ret;



}
@@ -781,7 +782,7 @@ static int gs_open(struct tty_struct *tty, struct file *file) 
static void gs_close(struct tty_struct *tty, struct file *file)

{

	struct gs_port *port = tty->driver_data;

	struct semaphore *sem;

	struct mutex *mtx;



	if (port == NULL) {

		printk(KERN_ERR "gs_close: NULL port pointer\n");
@@ -790,8 +791,8 @@ static void gs_close(struct tty_struct *tty, struct file *file) 


	gs_debug("gs_close: (%d,%p,%p)\n", port->port_num, tty, file);



	sem = &gs_open_close_sem[port->port_num];

	down(sem);

	mtx = &gs_open_close_lock[port->port_num];

	mutex_lock(mtx);



	spin_lock_irq(&port->port_lock);
@@ -846,7 +847,7 @@ static void gs_close(struct tty_struct *tty, struct file *file) 


exit:

	spin_unlock_irq(&port->port_lock);

	up(sem);

	mutex_unlock(mtx);

}



/*