V4L/DVB (7501): soc-camera: use a spinlock for videobuffer queue

All drivers should provide a spinlock to be used in videobuf operations.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Reviewed-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

3 files changed, 54 insertions, 5 deletions

diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c
index 9758f7eb5932..bef3c9c7902a 100644
--- a/drivers/media/video/pxa_camera.c
+++ b/drivers/media/video/pxa_camera.c
@@ -803,6 +803,15 @@ 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,
@@ -814,6 +823,7 @@ 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. */
diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index 43c8110599e8..1e921578804f 100644
--- a/drivers/media/video/soc_camera.c
+++ b/drivers/media/video/soc_camera.c
@@ -184,6 +184,7 @@ 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));
@@ -209,10 +210,16 @@ static int soc_camera_open(struct inode *inode, struct file *file)
                 goto emgi;
         }
 
-        icd->use_count++;
-
         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 */
         if (icd->use_count == 1) {
                 ret = ici->ops->add(icd);
@@ -229,8 +236,8 @@ static int soc_camera_open(struct inode *inode, struct file *file)
         dev_dbg(&icd->dev, "camera device open\n");
 
         /* We must pass NULL as dev pointer, then all pci_* dma operations
-         * transform to normal dma_* ones. Do we need an irqlock? */
-        videobuf_queue_sg_init(&icf->vb_vidq, ici->vbq_ops, NULL, NULL,
+         * transform to normal dma_* ones. */
+        videobuf_queue_sg_init(&icf->vb_vidq, ici->vbq_ops, NULL, icf->lock,
                                 V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
                                 ici->msize, icd);
 
@@ -238,6 +245,11 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 
         /* 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);
@@ -253,16 +265,20 @@ 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);
 
-        vfree(file->private_data);
+        vfree(icf);
 
         dev_dbg(vdev->dev, "camera device close\n");
 
@@ -762,6 +778,21 @@ 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;
@@ -792,6 +823,11 @@ 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;
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index 80e1193c07d5..6a8c8be7a1ae 100644
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -48,6 +48,7 @@ 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 {
@@ -73,6 +74,8 @@ struct soc_camera_host_ops {
         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 {