V4L/DVB (8338): soc_camera: Move spinlocks

This patch moves the spinlock handling from soc_camera.c to the actual
camera host driver. The spinlock_alloc/free callbacks are replaced with
code in init_videobuf(). So far all camera host drivers implement their
own spinlock_alloc/free methods anyway, and videobuf_queue_core_init()
BUGs on a NULL spinlock argument, so, new camera host drivers will not
forget to provide a spinlock when initialising their videobuf queues.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pxa_camera.c

@@ -583,12 +583,15 @@ static struct videobuf_queue_ops pxa_videobuf_ops = {
 	.buf_release    = pxa_videobuf_release,
 };
 
-static void pxa_camera_init_videobuf(struct videobuf_queue *q, spinlock_t *lock,
+static void pxa_camera_init_videobuf(struct videobuf_queue *q,
 			      struct soc_camera_device *icd)
 {
+	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+	struct pxa_camera_dev *pcdev = ici->priv;
+
 	/* We must pass NULL as dev pointer, then all pci_* dma operations
 	 * transform to normal dma_* ones. */
-	videobuf_queue_sg_init(q, &pxa_videobuf_ops, NULL, lock,
+	videobuf_queue_sg_init(q, &pxa_videobuf_ops, NULL, &pcdev->lock,
 				V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
 				sizeof(struct pxa_buffer), icd);
 }
@@ -994,15 +997,6 @@ static int pxa_camera_querycap(struct soc_camera_host *ici,
 	return 0;
 }
 
-static spinlock_t *pxa_camera_spinlock_alloc(struct soc_camera_file *icf)
-{
-	struct soc_camera_host *ici =
-		to_soc_camera_host(icf->icd->dev.parent);
-	struct pxa_camera_dev *pcdev = ici->priv;
-
-	return &pcdev->lock;
-}
-
 static struct soc_camera_host_ops pxa_soc_camera_host_ops = {
 	.owner		= THIS_MODULE,
 	.add		= pxa_camera_add_device,
@@ -1015,7 +1009,6 @@ static struct soc_camera_host_ops pxa_soc_camera_host_ops = {
 	.querycap	= pxa_camera_querycap,
 	.try_bus_param	= pxa_camera_try_bus_param,
 	.set_bus_param	= pxa_camera_set_bus_param,
-	.spinlock_alloc	= pxa_camera_spinlock_alloc,
 };
 
 /* Should be allocated dynamically too, but we have only one. */

drivers/media/video/soc_camera.c

@@ -183,7 +183,6 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 	struct soc_camera_device *icd;
 	struct soc_camera_host *ici;
 	struct soc_camera_file *icf;
-	spinlock_t *lock;
 	int ret;
 
 	icf = vmalloc(sizeof(*icf));
@@ -210,13 +209,6 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 	}
 
 	icf->icd = icd;
-
-	icf->lock = ici->ops->spinlock_alloc(icf);
-	if (!icf->lock) {
-		ret = -ENOMEM;
-		goto esla;
-	}
-
 	icd->use_count++;
 
 	/* Now we really have to activate the camera */
@@ -234,17 +226,12 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 	file->private_data = icf;
 	dev_dbg(&icd->dev, "camera device open\n");
 
-	ici->ops->init_videobuf(&icf->vb_vidq, icf->lock, icd);
+	ici->ops->init_videobuf(&icf->vb_vidq, icd);
 
 	return 0;
 
 	/* All errors are entered with the video_lock held */
 eiciadd:
-	lock = icf->lock;
-	icf->lock = NULL;
-	if (ici->ops->spinlock_free)
-		ici->ops->spinlock_free(lock);
-esla:
 	module_put(ici->ops->owner);
 emgi:
 	module_put(icd->ops->owner);
@@ -260,15 +247,11 @@ static int soc_camera_close(struct inode *inode, struct file *file)
 	struct soc_camera_device *icd = icf->icd;
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct video_device *vdev = icd->vdev;
-	spinlock_t *lock = icf->lock;
 
 	mutex_lock(&video_lock);
 	icd->use_count--;
 	if (!icd->use_count)
 		ici->ops->remove(icd);
-	icf->lock = NULL;
-	if (ici->ops->spinlock_free)
-		ici->ops->spinlock_free(lock);
 	module_put(icd->ops->owner);
 	module_put(ici->ops->owner);
 	mutex_unlock(&video_lock);
@@ -764,21 +747,6 @@ static void dummy_release(struct device *dev)
 {
 }
 
-static spinlock_t *spinlock_alloc(struct soc_camera_file *icf)
-{
-	spinlock_t *lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
-
-	if (lock)
-		spin_lock_init(lock);
-
-	return lock;
-}
-
-static void spinlock_free(spinlock_t *lock)
-{
-	kfree(lock);
-}
-
 int soc_camera_host_register(struct soc_camera_host *ici)
 {
 	int ret;
@@ -808,11 +776,6 @@ int soc_camera_host_register(struct soc_camera_host *ici)
 	if (ret)
 		goto edevr;
 
-	if (!ici->ops->spinlock_alloc) {
-		ici->ops->spinlock_alloc = spinlock_alloc;
-		ici->ops->spinlock_free = spinlock_free;
-	}
-
 	scan_add_host(ici);
 
 	return 0;

include/media/soc_camera.h

@@ -48,7 +48,6 @@ struct soc_camera_device {
 struct soc_camera_file {
 	struct soc_camera_device *icd;
 	struct videobuf_queue vb_vidq;
-	spinlock_t *lock;
 };
 
 struct soc_camera_host {
@@ -67,15 +66,13 @@ struct soc_camera_host_ops {
 	int (*set_fmt_cap)(struct soc_camera_device *, __u32,
 			   struct v4l2_rect *);
 	int (*try_fmt_cap)(struct soc_camera_device *, struct v4l2_format *);
-	void (*init_videobuf)(struct videobuf_queue*, spinlock_t *,
+	void (*init_videobuf)(struct videobuf_queue *,
 			      struct soc_camera_device *);
 	int (*reqbufs)(struct soc_camera_file *, struct v4l2_requestbuffers *);
 	int (*querycap)(struct soc_camera_host *, struct v4l2_capability *);
 	int (*try_bus_param)(struct soc_camera_device *, __u32);
 	int (*set_bus_param)(struct soc_camera_device *, __u32);
 	unsigned int (*poll)(struct file *, poll_table *);
-	spinlock_t* (*spinlock_alloc)(struct soc_camera_file *);
-	void (*spinlock_free)(spinlock_t *);
 };
 
 struct soc_camera_link {