interruptible_sleep_on is racy and going away. This replaces
one use in the radio-cadet driver with an open-coded
wait loop that lets us check the condition under the mutex
but sleep without it.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Hans Verkuil <hverkuil@xxxxxxxxx>
Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
---
drivers/media/radio/radio-cadet.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/media/radio/radio-cadet.c b/drivers/media/radio/radio-cadet.c
index 545c04c..67b5bbf 100644
--- a/drivers/media/radio/radio-cadet.c
+++ b/drivers/media/radio/radio-cadet.c
@@ -39,6 +39,7 @@
#include <linux/pnp.h>
#include <linux/sched.h>
#include <linux/io.h> /* outb, outb_p */
+#include <linux/wait.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
@@ -323,25 +324,32 @@ static ssize_t cadet_read(struct file *file, char __user *data, size_t count, lo
struct cadet *dev = video_drvdata(file);
unsigned char readbuf[RDS_BUFFER];
int i = 0;
+ DEFINE_WAIT(wait);
mutex_lock(&dev->lock);
if (dev->rdsstat == 0)
cadet_start_rds(dev);
- if (dev->rdsin == dev->rdsout) {
+ while (1) {
+ prepare_to_wait(&dev->read_queue, &wait, TASK_INTERRUPTIBLE);
+ if (dev->rdsin != dev->rdsout)
+ break;
+
if (file->f_flags & O_NONBLOCK) {
i = -EWOULDBLOCK;
goto unlock;
}
mutex_unlock(&dev->lock);
- interruptible_sleep_on(&dev->read_queue);
+ schedule();
mutex_lock(&dev->lock);
}
+
while (i < count && dev->rdsin != dev->rdsout)
readbuf[i++] = dev->rdsbuf[dev->rdsout++];
if (i && copy_to_user(data, readbuf, i))
i = -EFAULT;
unlock:
+ finish_wait(&dev->read_queue, &wait);
mutex_unlock(&dev->lock);
return i;
}
--
1.8.3.2
--
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