[media] v4l2-dev: vdev->v4l2_dev is always set, so simplify code
These days vdev->v4l2_dev must always be set. This means that some old code that still tests for a NULL vdev->v4l2_dev can be removed or simplified. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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@ -194,7 +194,7 @@ static void v4l2_device_release(struct device *cd)
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mutex_unlock(&videodev_lock);
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#if defined(CONFIG_MEDIA_CONTROLLER)
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if (v4l2_dev && v4l2_dev->mdev &&
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if (v4l2_dev->mdev &&
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vdev->vfl_type != VFL_TYPE_SUBDEV)
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media_device_unregister_entity(&vdev->entity);
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#endif
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@ -207,7 +207,7 @@ static void v4l2_device_release(struct device *cd)
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* TODO: In the long run all drivers that use v4l2_device should use the
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* v4l2_device release callback. This check will then be unnecessary.
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*/
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if (v4l2_dev && v4l2_dev->release == NULL)
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if (v4l2_dev->release == NULL)
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v4l2_dev = NULL;
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/* Release video_device and perform other
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@ -360,27 +360,22 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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* hack but it will have to do for those drivers that are not
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* yet converted to use unlocked_ioctl.
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*
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* There are two options: if the driver implements struct
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* v4l2_device, then the lock defined there is used to
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* serialize the ioctls. Otherwise the v4l2 core lock defined
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* below is used. This lock is really bad since it serializes
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* completely independent devices.
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* All drivers implement struct v4l2_device, so we use the
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* lock defined there to serialize the ioctls.
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*
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* Both variants suffer from the same problem: if the driver
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* sleeps, then it blocks all ioctls since the lock is still
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* held. This is very common for VIDIOC_DQBUF since that
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* normally waits for a frame to arrive. As a result any other
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* ioctl calls will proceed very, very slowly since each call
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* will have to wait for the VIDIOC_QBUF to finish. Things that
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* should take 0.01s may now take 10-20 seconds.
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* However, if the driver sleeps, then it blocks all ioctls
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* since the lock is still held. This is very common for
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* VIDIOC_DQBUF since that normally waits for a frame to arrive.
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* As a result any other ioctl calls will proceed very, very
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* slowly since each call will have to wait for the VIDIOC_QBUF
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* to finish. Things that should take 0.01s may now take 10-20
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* seconds.
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*
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* The workaround is to *not* take the lock for VIDIOC_DQBUF.
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* This actually works OK for videobuf-based drivers, since
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* videobuf will take its own internal lock.
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*/
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static DEFINE_MUTEX(v4l2_ioctl_mutex);
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struct mutex *m = vdev->v4l2_dev ?
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&vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
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struct mutex *m = &vdev->v4l2_dev->ioctl_lock;
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if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
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return -ERESTARTSYS;
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@ -938,12 +933,11 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
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name_base, nr, video_device_node_name(vdev));
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/* Increase v4l2_device refcount */
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if (vdev->v4l2_dev)
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v4l2_device_get(vdev->v4l2_dev);
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v4l2_device_get(vdev->v4l2_dev);
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#if defined(CONFIG_MEDIA_CONTROLLER)
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/* Part 5: Register the entity. */
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if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
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if (vdev->v4l2_dev->mdev &&
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vdev->vfl_type != VFL_TYPE_SUBDEV) {
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vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
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vdev->entity.name = vdev->name;
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