[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>

9 files changed, 35 insertions, 45 deletions

diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
index c8d748a31944..eba1f6b2b0fb 100644
--- a/drivers/media/platform/soc_camera/atmel-isi.c
+++ b/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);
diff --git a/drivers/media/platform/soc_camera/mx1_camera.c b/drivers/media/platform/soc_camera/mx1_camera.c
index 674ded646b66..4b661e87d8b1 100644
--- a/drivers/media/platform/soc_camera/mx1_camera.c
+++ b/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)
diff --git a/drivers/media/platform/soc_camera/mx2_camera.c b/drivers/media/platform/soc_camera/mx2_camera.c
index 28d5c84eef82..bf2740f7c4d1 100644
--- a/drivers/media/platform/soc_camera/mx2_camera.c
+++ b/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>
diff --git a/drivers/media/platform/soc_camera/mx3_camera.c b/drivers/media/platform/soc_camera/mx3_camera.c
index 574d12522f95..37d0d0ef8adf 100644
--- a/drivers/media/platform/soc_camera/mx3_camera.c
+++ b/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);
diff --git a/drivers/media/platform/soc_camera/omap1_camera.c b/drivers/media/platform/soc_camera/omap1_camera.c
index 8f9c1f44544c..dcf7be814776 100644
--- a/drivers/media/platform/soc_camera/omap1_camera.c
+++ b/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;
diff --git a/drivers/media/platform/soc_camera/pxa_camera.c b/drivers/media/platform/soc_camera/pxa_camera.c
index 8ff961eec39d..f3c1b6202425 100644
--- a/drivers/media/platform/soc_camera/pxa_camera.c
+++ b/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);
diff --git a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
index 9f021043cfe6..cdf173bbcc93 100644
--- a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
+++ b/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);
diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 6552856ea59b..ae89f980e82b 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/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 @@ egfmt:
         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 @@ esfmt:
 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)
 {
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index 0370a9517282..5a662c981484 100644
--- a/include/media/soc_camera.h
+++ b/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;