[media] soc-camera: remove struct soc_camera_device::video_lock

Currently soc-camera has a per-device node lock, used for video operations
and a per-host lock for code paths, modifying host's pipeline. Manipulating
the two locks increases complexity and doesn't bring any advantages. This
patch removes the per-device lock and uses the per-host lock for all
operations.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/soc_camera/atmel-isi.c

@@ -745,7 +745,7 @@ static int isi_camera_get_formats(struct soc_camera_device *icd,
 	return formats;
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static int isi_camera_add_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -770,7 +770,7 @@ static int isi_camera_add_device(struct soc_camera_device *icd)
 		 icd->devnum);
 	return 0;
 }
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static void isi_camera_remove_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

drivers/media/platform/soc_camera/mx1_camera.c

@@ -26,7 +26,6 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -373,7 +372,7 @@ static void mx1_camera_init_videobuf(struct videobuf_queue *q,
 	videobuf_queue_dma_contig_init(q, &mx1_videobuf_ops, icd->parent,
 				&pcdev->lock, V4L2_BUF_TYPE_VIDEO_CAPTURE,
 				V4L2_FIELD_NONE,
-				sizeof(struct mx1_buffer), icd, &icd->video_lock);
+				sizeof(struct mx1_buffer), icd, &icd->host_lock);
 }
 
 static int mclk_get_divisor(struct mx1_camera_dev *pcdev)

drivers/media/platform/soc_camera/mx2_camera.c

@@ -28,7 +28,6 @@
 #include <linux/time.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
-#include <linux/mutex.h>
 #include <linux/clk.h>
 
 #include <media/v4l2-common.h>

drivers/media/platform/soc_camera/mx3_camera.c

@@ -510,7 +510,7 @@ static void mx3_camera_activate(struct mx3_camera_dev *mx3_cam,
 		clk_set_rate(mx3_cam->clk, rate);
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static int mx3_camera_add_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -530,7 +530,7 @@ static int mx3_camera_add_device(struct soc_camera_device *icd)
 	return 0;
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static void mx3_camera_remove_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

drivers/media/platform/soc_camera/omap1_camera.c

@@ -1383,12 +1383,12 @@ static void omap1_cam_init_videobuf(struct videobuf_queue *q,
 		videobuf_queue_dma_contig_init(q, &omap1_videobuf_ops,
 				icd->parent, &pcdev->lock,
 				V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
-				sizeof(struct omap1_cam_buf), icd, &icd->video_lock);
+				sizeof(struct omap1_cam_buf), icd, &icd->host_lock);
 	else
 		videobuf_queue_sg_init(q, &omap1_videobuf_ops,
 				icd->parent, &pcdev->lock,
 				V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
-				sizeof(struct omap1_cam_buf), icd, &icd->video_lock);
+				sizeof(struct omap1_cam_buf), icd, &icd->host_lock);
 
 	/* use videobuf mode (auto)selected with the module parameter */
 	pcdev->vb_mode = sg_mode ? OMAP1_CAM_DMA_SG : OMAP1_CAM_DMA_CONTIG;

drivers/media/platform/soc_camera/pxa_camera.c

@@ -842,7 +842,7 @@ static void pxa_camera_init_videobuf(struct videobuf_queue *q,
 	 */
 	videobuf_queue_sg_init(q, &pxa_videobuf_ops, NULL, &pcdev->lock,
 				V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
-				sizeof(struct pxa_buffer), icd, &icd->video_lock);
+				sizeof(struct pxa_buffer), icd, &icd->host_lock);
 }
 
 static u32 mclk_get_divisor(struct platform_device *pdev,
@@ -958,7 +958,7 @@ static irqreturn_t pxa_camera_irq(int irq, void *data)
 /*
  * The following two functions absolutely depend on the fact, that
  * there can be only one camera on PXA quick capture interface
- * Called with .video_lock held
+ * Called with .host_lock held
  */
 static int pxa_camera_add_device(struct soc_camera_device *icd)
 {
@@ -978,7 +978,7 @@ static int pxa_camera_add_device(struct soc_camera_device *icd)
 	return 0;
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static void pxa_camera_remove_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c

@@ -543,7 +543,7 @@ static struct v4l2_subdev *find_csi2(struct sh_mobile_ceu_dev *pcdev)
 	return NULL;
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static int sh_mobile_ceu_add_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -587,7 +587,7 @@ static int sh_mobile_ceu_add_device(struct soc_camera_device *icd)
 	return 0;
 }
 
-/* Called with .video_lock held */
+/* Called with .host_lock held */
 static void sh_mobile_ceu_remove_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

drivers/media/platform/soc_camera/soc_camera.c

@@ -383,7 +383,7 @@ static int soc_camera_prepare_buf(struct file *file, void *priv,
 		return vb2_prepare_buf(&icd->vb2_vidq, b);
 }
 
-/* Always entered with .video_lock held */
+/* Always entered with .host_lock held */
 static int soc_camera_init_user_formats(struct soc_camera_device *icd)
 {
 	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
@@ -450,7 +450,7 @@ static int soc_camera_init_user_formats(struct soc_camera_device *icd)
 	return ret;
 }
 
-/* Always entered with .video_lock held */
+/* Always entered with .host_lock held */
 static void soc_camera_free_user_formats(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -526,7 +526,7 @@ static int soc_camera_open(struct file *file)
 	ici = to_soc_camera_host(icd->parent);
 	mutex_unlock(&list_lock);
 
-	if (mutex_lock_interruptible(&icd->video_lock))
+	if (mutex_lock_interruptible(&ici->host_lock))
 		return -ERESTARTSYS;
 	if (!try_module_get(ici->ops->owner)) {
 		dev_err(icd->pdev, "Couldn't lock capture bus driver.\n");
@@ -555,9 +555,7 @@ static int soc_camera_open(struct file *file)
 		if (icl->reset)
 			icl->reset(icd->pdev);
 
-		mutex_lock(&ici->host_lock);
 		ret = ici->ops->add(icd);
-		mutex_unlock(&ici->host_lock);
 		if (ret < 0) {
 			dev_err(icd->pdev, "Couldn't activate the camera: %d\n", ret);
 			goto eiciadd;
@@ -576,7 +574,7 @@ static int soc_camera_open(struct file *file)
 		 * Try to configure with default parameters. Notice: this is the
 		 * very first open, so, we cannot race against other calls,
 		 * apart from someone else calling open() simultaneously, but
-		 * .video_lock is protecting us against it.
+		 * .host_lock is protecting us against it.
 		 */
 		ret = soc_camera_set_fmt(icd, &f);
 		if (ret < 0)
@@ -591,7 +589,7 @@ static int soc_camera_open(struct file *file)
 		}
 		v4l2_ctrl_handler_setup(&icd->ctrl_handler);
 	}
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 
 	file->private_data = icd;
 	dev_dbg(icd->pdev, "camera device open\n");
@@ -599,7 +597,7 @@ static int soc_camera_open(struct file *file)
 	return 0;
 
 	/*
-	 * First four errors are entered with the .video_lock held
+	 * First four errors are entered with the .host_lock held
 	 * and use_count == 1
 	 */
 einitvb:
@@ -608,14 +606,12 @@ static int soc_camera_open(struct file *file)
 eresume:
 	__soc_camera_power_off(icd);
 epower:
-	mutex_lock(&ici->host_lock);
 	ici->ops->remove(icd);
-	mutex_unlock(&ici->host_lock);
 eiciadd:
 	icd->use_count--;
 	module_put(ici->ops->owner);
 emodule:
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 
 	return ret;
 }
@@ -625,7 +621,7 @@ static int soc_camera_close(struct file *file)
 	struct soc_camera_device *icd = file->private_data;
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
 
-	mutex_lock(&icd->video_lock);
+	mutex_lock(&ici->host_lock);
 	icd->use_count--;
 	if (!icd->use_count) {
 		pm_runtime_suspend(&icd->vdev->dev);
@@ -633,16 +629,14 @@ static int soc_camera_close(struct file *file)
 
 		if (ici->ops->init_videobuf2)
 			vb2_queue_release(&icd->vb2_vidq);
-		mutex_lock(&ici->host_lock);
 		ici->ops->remove(icd);
-		mutex_unlock(&ici->host_lock);
 
 		__soc_camera_power_off(icd);
 	}
 
 	if (icd->streamer == file)
 		icd->streamer = NULL;
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 
 	module_put(ici->ops->owner);
 
@@ -679,13 +673,13 @@ static int soc_camera_mmap(struct file *file, struct vm_area_struct *vma)
 	if (icd->streamer != file)
 		return -EBUSY;
 
-	if (mutex_lock_interruptible(&icd->video_lock))
+	if (mutex_lock_interruptible(&ici->host_lock))
 		return -ERESTARTSYS;
 	if (ici->ops->init_videobuf)
 		err = videobuf_mmap_mapper(&icd->vb_vidq, vma);
 	else
 		err = vb2_mmap(&icd->vb2_vidq, vma);
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 
 	dev_dbg(icd->pdev, "vma start=0x%08lx, size=%ld, ret=%d\n",
 		(unsigned long)vma->vm_start,
@@ -704,26 +698,28 @@ static unsigned int soc_camera_poll(struct file *file, poll_table *pt)
 	if (icd->streamer != file)
 		return POLLERR;
 
-	mutex_lock(&icd->video_lock);
+	mutex_lock(&ici->host_lock);
 	if (ici->ops->init_videobuf && list_empty(&icd->vb_vidq.stream))
 		dev_err(icd->pdev, "Trying to poll with no queued buffers!\n");
 	else
 		res = ici->ops->poll(file, pt);
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 	return res;
 }
 
 void soc_camera_lock(struct vb2_queue *vq)
 {
 	struct soc_camera_device *icd = vb2_get_drv_priv(vq);
-	mutex_lock(&icd->video_lock);
+	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
+	mutex_lock(&ici->host_lock);
 }
 EXPORT_SYMBOL(soc_camera_lock);
 
 void soc_camera_unlock(struct vb2_queue *vq)
 {
 	struct soc_camera_device *icd = vb2_get_drv_priv(vq);
-	mutex_unlock(&icd->video_lock);
+	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
+	mutex_unlock(&ici->host_lock);
 }
 EXPORT_SYMBOL(soc_camera_unlock);
 
@@ -1213,7 +1209,7 @@ static int soc_camera_probe(struct soc_camera_device *icd)
 	 * itself is protected against concurrent open() calls, but we also have
 	 * to protect our data.
 	 */
-	mutex_lock(&icd->video_lock);
+	mutex_lock(&ici->host_lock);
 
 	ret = soc_camera_video_start(icd);
 	if (ret < 0)
@@ -1227,16 +1223,14 @@ static int soc_camera_probe(struct soc_camera_device *icd)
 		icd->field		= mf.field;
 	}
 
-	mutex_lock(&ici->host_lock);
 	ici->ops->remove(icd);
-	mutex_unlock(&ici->host_lock);
 
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 
 	return 0;
 
 evidstart:
-	mutex_unlock(&icd->video_lock);
+	mutex_unlock(&ici->host_lock);
 	soc_camera_free_user_formats(icd);
 eiufmt:
 ectrl:
@@ -1451,7 +1445,6 @@ static int soc_camera_device_register(struct soc_camera_device *icd)
 	icd->devnum		= num;
 	icd->use_count		= 0;
 	icd->host_priv		= NULL;
-	mutex_init(&icd->video_lock);
 
 	list_add_tail(&icd->list, &devices);
 
@@ -1509,7 +1502,7 @@ static int video_dev_create(struct soc_camera_device *icd)
 	vdev->release		= video_device_release;
 	vdev->tvnorms		= V4L2_STD_UNKNOWN;
 	vdev->ctrl_handler	= &icd->ctrl_handler;
-	vdev->lock		= &icd->video_lock;
+	vdev->lock		= &ici->host_lock;
 
 	icd->vdev = vdev;
 
@@ -1517,7 +1510,7 @@ static int video_dev_create(struct soc_camera_device *icd)
 }
 
 /*
- * Called from soc_camera_probe() above (with .video_lock held???)
+ * Called from soc_camera_probe() above with .host_lock held
  */
 static int soc_camera_video_start(struct soc_camera_device *icd)
 {

include/media/soc_camera.h

@@ -46,9 +46,8 @@ struct soc_camera_device {
 	int num_user_formats;
 	enum v4l2_field field;		/* Preserve field over close() */
 	void *host_priv;		/* Per-device host private data */
-	/* soc_camera.c private count. Only accessed with .video_lock held */
+	/* soc_camera.c private count. Only accessed with .host_lock held */
 	int use_count;
-	struct mutex video_lock;	/* Protects device data */
 	struct file *streamer;		/* stream owner */
 	union {
 		struct videobuf_queue vb_vidq;