diff options
| -rw-r--r-- | drivers/media/video/soc_camera.c | 52 | ||||
| -rw-r--r-- | include/media/soc_camera.h | 2 |
2 files changed, 41 insertions, 13 deletions
diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c index c947525c3f2..322f837bcfe 100644 --- a/drivers/media/video/soc_camera.c +++ b/drivers/media/video/soc_camera.c @@ -179,11 +179,9 @@ static int soc_camera_dqbuf(struct file *file, void *priv, static int soc_camera_open(struct inode *inode, struct file *file) { - struct video_device *vdev = video_devdata(file); - struct soc_camera_device *icd = container_of(vdev->dev, - struct soc_camera_device, dev); - struct soc_camera_host *ici = - to_soc_camera_host(icd->dev.parent); + struct video_device *vdev; + struct soc_camera_device *icd; + struct soc_camera_host *ici; struct soc_camera_file *icf; int ret; @@ -191,7 +189,12 @@ static int soc_camera_open(struct inode *inode, struct file *file) if (!icf) return -ENOMEM; - icf->icd = icd; + /* Protect against icd->remove() until we module_get() both drivers. */ + mutex_lock(&video_lock); + + vdev = video_devdata(file); + icd = container_of(vdev->dev, struct soc_camera_device, dev); + ici = to_soc_camera_host(icd->dev.parent); if (!try_module_get(icd->ops->owner)) { dev_err(&icd->dev, "Couldn't lock sensor driver.\n"); @@ -205,6 +208,22 @@ static int soc_camera_open(struct inode *inode, struct file *file) goto emgi; } + icd->use_count++; + + icf->icd = icd; + + /* Now we really have to activate the camera */ + if (icd->use_count == 1) { + ret = ici->add(icd); + if (ret < 0) { + dev_err(&icd->dev, "Couldn't activate the camera: %d\n", ret); + icd->use_count--; + goto eiciadd; + } + } + + mutex_unlock(&video_lock); + file->private_data = icf; dev_dbg(&icd->dev, "camera device open\n"); @@ -216,9 +235,13 @@ static int soc_camera_open(struct inode *inode, struct file *file) return 0; + /* All errors are entered with the video_lock held */ +eiciadd: + module_put(ici->owner); emgi: module_put(icd->ops->owner); emgd: + mutex_unlock(&video_lock); vfree(icf); return ret; } @@ -230,8 +253,14 @@ static int soc_camera_close(struct inode *inode, struct file *file) struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent); struct video_device *vdev = icd->vdev; + mutex_lock(&video_lock); + icd->use_count--; + if (!icd->use_count) + ici->remove(icd); module_put(icd->ops->owner); module_put(ici->owner); + mutex_unlock(&video_lock); + vfree(file->private_data); dev_dbg(vdev->dev, "camera device close\n"); @@ -673,14 +702,14 @@ static int soc_camera_probe(struct device *dev) if (!icd->probe) return -ENODEV; + /* We only call ->add() here to activate and probe the camera. + * We shall ->remove() and deactivate it immediately afterwards. */ ret = ici->add(icd); if (ret < 0) return ret; ret = icd->probe(icd); - if (ret < 0) - ici->remove(icd); - else { + if (ret >= 0) { const struct v4l2_queryctrl *qctrl; qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_GAIN); @@ -689,6 +718,7 @@ static int soc_camera_probe(struct device *dev) icd->exposure = qctrl ? qctrl->default_value : (unsigned short)~0; } + ici->remove(icd); return ret; } @@ -698,14 +728,10 @@ static int soc_camera_probe(struct device *dev) static int soc_camera_remove(struct device *dev) { struct soc_camera_device *icd = to_soc_camera_dev(dev); - struct soc_camera_host *ici = - to_soc_camera_host(icd->dev.parent); if (icd->remove) icd->remove(icd); - ici->remove(icd); - return 0; } diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h index 69aba7188e4..c886b1e6487 100644 --- a/include/media/soc_camera.h +++ b/include/media/soc_camera.h @@ -41,6 +41,8 @@ struct soc_camera_device { int (*probe)(struct soc_camera_device *icd); void (*remove)(struct soc_camera_device *icd); struct module *owner; + /* soc_camera.c private count. Only accessed with video_lock held */ + int use_count; }; struct soc_camera_file { |