[media] cx88: don't use atomic_t for core->mpeg_users
Jonathan Nieder [Sun, 1 May 2011 09:31:04 +0000 (06:31 -0300)]
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.

Tested-by: Andi Huber <hobrom@gmx.at>
Tested-by: Marlon de Boer <marlon@hyves.nl>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx88/cx88-blackbird.c
drivers/media/video/cx88/cx88.h

index fa8e347..11e49bb 100644 (file)
@@ -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);
 
index 3d32f4a..9e8176e 100644 (file)
@@ -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;