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Subject[PATCH 6/7] [media] cx88: don't use atomic_t for core->mpeg_users
mpeg_users is always read or written with core->lock held except
in mpeg_release (where it looks like a bug). A plain int is simpler
and faster.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
drivers/media/video/cx88/cx88-blackbird.c | 11 ++++++-----
drivers/media/video/cx88/cx88.h | 2 +-
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/media/video/cx88/cx88-blackbird.c b/drivers/media/video/cx88/cx88-blackbird.c
index fa8e347..11e49bb 100644
--- a/drivers/media/video/cx88/cx88-blackbird.c
+++ b/drivers/media/video/cx88/cx88-blackbird.c
@@ -1073,7 +1073,7 @@ static int mpeg_open(struct file *file)
return err;
}

- if (!atomic_read(&dev->core->mpeg_users) && blackbird_initialize_codec(dev) < 0) {
+ if (!dev->core->mpeg_users && blackbird_initialize_codec(dev) < 0) {
drv->request_release(drv);
mutex_unlock(&dev->core->lock);
return -EINVAL;
@@ -1101,7 +1101,7 @@ static int mpeg_open(struct file *file)
cx88_set_scale(dev->core, dev->width, dev->height,
fh->mpegq.field);

- atomic_inc(&dev->core->mpeg_users);
+ dev->core->mpeg_users++;
mutex_unlock(&dev->core->lock);
return 0;
}
@@ -1112,7 +1112,9 @@ static int mpeg_release(struct file *file)
struct cx8802_dev *dev = fh->dev;
struct cx8802_driver *drv = NULL;

- if (dev->mpeg_active && atomic_read(&dev->core->mpeg_users) == 1)
+ mutex_lock(&dev->core->lock);
+
+ if (dev->mpeg_active && dev->core->mpeg_users == 1)
blackbird_stop_codec(dev);

cx8802_cancel_buffers(fh->dev);
@@ -1121,7 +1123,6 @@ static int mpeg_release(struct file *file)

videobuf_mmap_free(&fh->mpegq);

- mutex_lock(&dev->core->lock);
file->private_data = NULL;
kfree(fh);

@@ -1131,7 +1132,7 @@ static int mpeg_release(struct file *file)
if (drv)
drv->request_release(drv);

- atomic_dec(&dev->core->mpeg_users);
+ dev->core->mpeg_users--;

mutex_unlock(&dev->core->lock);

diff --git a/drivers/media/video/cx88/cx88.h b/drivers/media/video/cx88/cx88.h
index 3d32f4a..9e8176e 100644
--- a/drivers/media/video/cx88/cx88.h
+++ b/drivers/media/video/cx88/cx88.h
@@ -390,7 +390,7 @@ struct cx88_core {
/* various v4l controls */
u32 freq;
atomic_t users;
- atomic_t mpeg_users;
+ int mpeg_users;

/* cx88-video needs to access cx8802 for hybrid tuner pll access. */
struct cx8802_dev *dvbdev;
--
1.7.5.rc0


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