Commit ce0ede2c authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[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
...@@ -270,6 +270,16 @@ static void cadet_setfreq(struct cadet *dev, unsigned freq) ...@@ -270,6 +270,16 @@ static void cadet_setfreq(struct cadet *dev, unsigned freq)
outb(inb(dev->io + 1) & 0x7f, dev->io + 1); 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) static void cadet_handler(unsigned long data)
{ {
...@@ -279,13 +289,12 @@ static void cadet_handler(unsigned long data) ...@@ -279,13 +289,12 @@ static void cadet_handler(unsigned long data)
if (mutex_trylock(&dev->lock)) { if (mutex_trylock(&dev->lock)) {
outb(0x3, dev->io); /* Select RDS Decoder Control */ outb(0x3, dev->io); /* Select RDS Decoder Control */
if ((inb(dev->io + 1) & 0x20) != 0) 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 */ outb(0x80, dev->io); /* Select RDS fifo */
while ((inb(dev->io) & 0x80) != 0) { while ((inb(dev->io) & 0x80) != 0) {
dev->rdsbuf[dev->rdsin] = inb(dev->io + 1); dev->rdsbuf[dev->rdsin] = inb(dev->io + 1);
if (dev->rdsin + 1 == dev->rdsout) if (dev->rdsin + 1 != dev->rdsout)
printk(KERN_WARNING "cadet: RDS buffer overflow\n");
else
dev->rdsin++; dev->rdsin++;
} }
mutex_unlock(&dev->lock); mutex_unlock(&dev->lock);
...@@ -294,7 +303,7 @@ static void cadet_handler(unsigned long data) ...@@ -294,7 +303,7 @@ static void cadet_handler(unsigned long data)
/* /*
* Service pending read * Service pending read
*/ */
if (dev->rdsin != dev->rdsout) if (cadet_has_rds_data(dev))
wake_up_interruptible(&dev->read_queue); 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 ...@@ -327,22 +336,21 @@ static ssize_t cadet_read(struct file *file, char __user *data, size_t count, lo
mutex_lock(&dev->lock); mutex_lock(&dev->lock);
if (dev->rdsstat == 0) if (dev->rdsstat == 0)
cadet_start_rds(dev); cadet_start_rds(dev);
if (dev->rdsin == dev->rdsout) { mutex_unlock(&dev->lock);
if (file->f_flags & O_NONBLOCK) {
i = -EWOULDBLOCK; if (!cadet_has_rds_data(dev) && (file->f_flags & O_NONBLOCK))
goto unlock; return -EWOULDBLOCK;
} i = wait_event_interruptible(dev->read_queue, cadet_has_rds_data(dev));
mutex_unlock(&dev->lock); if (i)
interruptible_sleep_on(&dev->read_queue); return i;
mutex_lock(&dev->lock);
} mutex_lock(&dev->lock);
while (i < count && dev->rdsin != dev->rdsout) while (i < count && dev->rdsin != dev->rdsout)
readbuf[i++] = dev->rdsbuf[dev->rdsout++]; readbuf[i++] = dev->rdsbuf[dev->rdsout++];
mutex_unlock(&dev->lock);
if (i && copy_to_user(data, readbuf, i)) if (i && copy_to_user(data, readbuf, i))
i = -EFAULT; return -EFAULT;
unlock:
mutex_unlock(&dev->lock);
return i; return i;
} }
...@@ -352,7 +360,7 @@ static int vidioc_querycap(struct file *file, void *priv, ...@@ -352,7 +360,7 @@ static int vidioc_querycap(struct file *file, void *priv,
{ {
strlcpy(v->driver, "ADS Cadet", sizeof(v->driver)); strlcpy(v->driver, "ADS Cadet", sizeof(v->driver));
strlcpy(v->card, "ADS Cadet", sizeof(v->card)); 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 | v->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE; V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;
v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS; 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 ...@@ -491,7 +499,7 @@ static unsigned int cadet_poll(struct file *file, struct poll_table_struct *wait
cadet_start_rds(dev); cadet_start_rds(dev);
mutex_unlock(&dev->lock); mutex_unlock(&dev->lock);
} }
if (dev->rdsin != dev->rdsout) if (cadet_has_rds_data(dev))
res |= POLLIN | POLLRDNORM; res |= POLLIN | POLLRDNORM;
return res; return res;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment