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Commit ce0ede2c authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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[media] radio-cadet: avoid interruptible_sleep_on race 



interruptible_sleep_on is racy and going away. This replaces
one use in the radio-cadet driver with a wait_event_interruptible
call. Special care was taken that accesses to the rdsin and rdsout
indices are always done with dev->lock held.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 2dfb1c93

drivers/media/radio/radio-cadet.c

+27 −19
Original line number Diff line number Diff line
@@ -270,6 +270,16 @@ reset_rds: 
	outb(inb(dev->io + 1) & 0x7f, dev->io + 1);

}



static bool cadet_has_rds_data(struct cadet *dev)

{

	bool result;



	mutex_lock(&dev->lock);

	result = dev->rdsin != dev->rdsout;

	mutex_unlock(&dev->lock);

	return result;

}





static void cadet_handler(unsigned long data)

{
@@ -279,13 +289,12 @@ static void cadet_handler(unsigned long data) 
	if (mutex_trylock(&dev->lock)) {

		outb(0x3, dev->io);       /* Select RDS Decoder Control */

		if ((inb(dev->io + 1) & 0x20) != 0)

			printk(KERN_CRIT "cadet: RDS fifo overflow\n");

			pr_err("cadet: RDS fifo overflow\n");

		outb(0x80, dev->io);      /* Select RDS fifo */



		while ((inb(dev->io) & 0x80) != 0) {

			dev->rdsbuf[dev->rdsin] = inb(dev->io + 1);

			if (dev->rdsin + 1 == dev->rdsout)

				printk(KERN_WARNING "cadet: RDS buffer overflow\n");

			else

			if (dev->rdsin + 1 != dev->rdsout)

				dev->rdsin++;

		}

		mutex_unlock(&dev->lock);
@@ -294,7 +303,7 @@ static void cadet_handler(unsigned long data) 
	/*

	 * Service pending read

	 */

	if (dev->rdsin != dev->rdsout)

	if (cadet_has_rds_data(dev))

		wake_up_interruptible(&dev->read_queue);



	/*
@@ -327,22 +336,21 @@ static ssize_t cadet_read(struct file *file, char __user *data, size_t count, lo 
	mutex_lock(&dev->lock);

	if (dev->rdsstat == 0)

		cadet_start_rds(dev);

	if (dev->rdsin == dev->rdsout) {

		if (file->f_flags & O_NONBLOCK) {

			i = -EWOULDBLOCK;

			goto unlock;

		}

	mutex_unlock(&dev->lock);

		interruptible_sleep_on(&dev->read_queue);



	if (!cadet_has_rds_data(dev) && (file->f_flags & O_NONBLOCK))

		return -EWOULDBLOCK;

	i = wait_event_interruptible(dev->read_queue, cadet_has_rds_data(dev));

	if (i)

		return i;



	mutex_lock(&dev->lock);

	}

	while (i < count && dev->rdsin != dev->rdsout)

		readbuf[i++] = dev->rdsbuf[dev->rdsout++];

	mutex_unlock(&dev->lock);



	if (i && copy_to_user(data, readbuf, i))

		i = -EFAULT;

unlock:

	mutex_unlock(&dev->lock);

		return -EFAULT;

	return i;

}
@@ -352,7 +360,7 @@ static int vidioc_querycap(struct file *file, void *priv, 
{

	strlcpy(v->driver, "ADS Cadet", sizeof(v->driver));

	strlcpy(v->card, "ADS Cadet", sizeof(v->card));

	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));

	strlcpy(v->bus_info, "ISA:radio-cadet", sizeof(v->bus_info));

	v->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |

			  V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;

	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
@@ -491,7 +499,7 @@ static unsigned int cadet_poll(struct file *file, struct poll_table_struct *wait 
			cadet_start_rds(dev);

		mutex_unlock(&dev->lock);

	}

	if (dev->rdsin != dev->rdsout)

	if (cadet_has_rds_data(dev))

		res |= POLLIN | POLLRDNORM;

	return res;

}