[media] gspca: Switch to V4L2 core locking, except for the buffer queuing ioctls

Due to latency concerns the VIDIOC_QBUF, DQBUF and QUERYBUF do not use the
core lock, instead they rely only on queue_lock.

Changes by HdG:
1) Change release from the video_device to the v4l2_device, to avoid a
race on disconnect.
2) Adjust for the V4L2 core changes which cause non ioctl fops to no longer
take the V4L2 core lock.

[mchehab@redhat.com: fix a merge conflict]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 76 insertions, 181 deletions

diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index a14c8f71d48b..2687e76b0fb8 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -850,14 +850,6 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
         struct ep_tb_s ep_tb[MAX_ALT];
         int n, ret, xfer, alt, alt_idx;
 
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
-
-        if (!gspca_dev->present) {
-                ret = -ENODEV;
-                goto unlock;
-        }
-
         /* reset the streaming variables */
         gspca_dev->image = NULL;
         gspca_dev->image_len = 0;
@@ -872,7 +864,7 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
         if (gspca_dev->sd_desc->isoc_init) {
                 ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
                 if (ret < 0)
-                        goto unlock;
+                        return ret;
         }
         xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
                                    : USB_ENDPOINT_XFER_ISOC;
@@ -883,8 +875,7 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
                 ep = alt_xfer(&intf->altsetting[gspca_dev->alt], xfer);
                 if (ep == NULL) {
                         pr_err("bad altsetting %d\n", gspca_dev->alt);
-                        ret = -EIO;
-                        goto out;
+                        return -EIO;
                 }
                 ep_tb[0].alt = gspca_dev->alt;
                 alt_idx = 1;
@@ -895,8 +886,7 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
                 alt_idx = build_isoc_ep_tb(gspca_dev, intf, ep_tb);
                 if (alt_idx <= 0) {
                         pr_err("no transfer endpoint found\n");
-                        ret = -EIO;
-                        goto unlock;
+                        return -EIO;
                 }
         }
 
@@ -991,8 +981,6 @@ retry:
         }
 out:
         gspca_input_create_urb(gspca_dev);
-unlock:
-        mutex_unlock(&gspca_dev->usb_lock);
         return ret;
 }
 
@@ -1062,7 +1050,6 @@ static int gspca_get_mode(struct gspca_dev *gspca_dev,
 static int vidioc_g_register(struct file *file, void *priv,
                         struct v4l2_dbg_register *reg)
 {
-        int ret;
         struct gspca_dev *gspca_dev = video_drvdata(file);
 
         if (!gspca_dev->sd_desc->get_chip_ident)
@@ -1071,22 +1058,13 @@ static int vidioc_g_register(struct file *file, void *priv,
         if (!gspca_dev->sd_desc->get_register)
                 return -ENOTTY;
 
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
         gspca_dev->usb_err = 0;
-        if (gspca_dev->present)
-                ret = gspca_dev->sd_desc->get_register(gspca_dev, reg);
-        else
-                ret = -ENODEV;
-        mutex_unlock(&gspca_dev->usb_lock);
-
-        return ret;
+        return gspca_dev->sd_desc->get_register(gspca_dev, reg);
 }
 
 static int vidioc_s_register(struct file *file, void *priv,
                         struct v4l2_dbg_register *reg)
 {
-        int ret;
         struct gspca_dev *gspca_dev = video_drvdata(file);
 
         if (!gspca_dev->sd_desc->get_chip_ident)
@@ -1095,38 +1073,21 @@ static int vidioc_s_register(struct file *file, void *priv,
         if (!gspca_dev->sd_desc->set_register)
                 return -ENOTTY;
 
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
         gspca_dev->usb_err = 0;
-        if (gspca_dev->present)
-                ret = gspca_dev->sd_desc->set_register(gspca_dev, reg);
-        else
-                ret = -ENODEV;
-        mutex_unlock(&gspca_dev->usb_lock);
-
-        return ret;
+        return gspca_dev->sd_desc->set_register(gspca_dev, reg);
 }
 #endif
 
 static int vidioc_g_chip_ident(struct file *file, void *priv,
                         struct v4l2_dbg_chip_ident *chip)
 {
-        int ret;
         struct gspca_dev *gspca_dev = video_drvdata(file);
 
         if (!gspca_dev->sd_desc->get_chip_ident)
                 return -ENOTTY;
 
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
         gspca_dev->usb_err = 0;
-        if (gspca_dev->present)
-                ret = gspca_dev->sd_desc->get_chip_ident(gspca_dev, chip);
-        else
-                ret = -ENODEV;
-        mutex_unlock(&gspca_dev->usb_lock);
-
-        return ret;
+        return gspca_dev->sd_desc->get_chip_ident(gspca_dev, chip);
 }
 
 static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
@@ -1321,9 +1282,10 @@ static int vidioc_enum_frameintervals(struct file *filp, void *priv,
         return -EINVAL;
 }
 
-static void gspca_release(struct video_device *vfd)
+static void gspca_release(struct v4l2_device *v4l2_device)
 {
-        struct gspca_dev *gspca_dev = container_of(vfd, struct gspca_dev, vdev);
+        struct gspca_dev *gspca_dev =
+                container_of(v4l2_device, struct gspca_dev, v4l2_dev);
 
         PDEBUG(D_PROBE, "%s released",
                 video_device_node_name(&gspca_dev->vdev));
@@ -1339,8 +1301,6 @@ static int dev_open(struct file *file)
         struct gspca_dev *gspca_dev = video_drvdata(file);
 
         PDEBUG(D_STREAM, "[%s] open", current->comm);
-        if (!gspca_dev->present)
-                return -ENODEV;
 
         /* protect the subdriver against rmmod */
         if (!try_module_get(gspca_dev->module))
@@ -1363,21 +1323,27 @@ static int dev_close(struct file *file)
         struct gspca_dev *gspca_dev = video_drvdata(file);
 
         PDEBUG(D_STREAM, "[%s] close", current->comm);
-        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
+
+        /* Needed for gspca_stream_off, always lock before queue_lock! */
+        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
                 return -ERESTARTSYS;
 
+        if (mutex_lock_interruptible(&gspca_dev->queue_lock)) {
+                mutex_unlock(&gspca_dev->usb_lock);
+                return -ERESTARTSYS;
+        }
+
         /* if the file did the capture, free the streaming resources */
         if (gspca_dev->capt_file == file) {
                 if (gspca_dev->streaming) {
-                        mutex_lock(&gspca_dev->usb_lock);
                         gspca_dev->usb_err = 0;
                         gspca_stream_off(gspca_dev);
-                        mutex_unlock(&gspca_dev->usb_lock);
                 }
                 frame_free(gspca_dev);
         }
         module_put(gspca_dev->module);
         mutex_unlock(&gspca_dev->queue_lock);
+        mutex_unlock(&gspca_dev->usb_lock);
 
         PDEBUG(D_STREAM, "close done");
 
@@ -1388,15 +1354,7 @@ static int vidioc_querycap(struct file *file, void  *priv,
                            struct v4l2_capability *cap)
 {
         struct gspca_dev *gspca_dev = video_drvdata(file);
-        int ret;
 
-        /* protect the access to the usb device */
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
-        if (!gspca_dev->present) {
-                ret = -ENODEV;
-                goto out;
-        }
         strlcpy((char *) cap->driver, gspca_dev->sd_desc->name,
                         sizeof cap->driver);
         if (gspca_dev->dev->product != NULL) {
@@ -1414,10 +1372,7 @@ static int vidioc_querycap(struct file *file, void  *priv,
                           | V4L2_CAP_STREAMING
                           | V4L2_CAP_READWRITE;
         cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
-        ret = 0;
-out:
-        mutex_unlock(&gspca_dev->usb_lock);
-        return ret;
+        return 0;
 }
 
 static int get_ctrl(struct gspca_dev *gspca_dev,
@@ -1486,7 +1441,7 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
         struct gspca_dev *gspca_dev = video_drvdata(file);
         const struct ctrl *ctrls;
         struct gspca_ctrl *gspca_ctrl;
-        int idx, ret;
+        int idx;
 
         idx = get_ctrl(gspca_dev, ctrl->id);
         if (idx < 0)
@@ -1506,27 +1461,16 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
                         return -ERANGE;
         }
         PDEBUG(D_CONF, "set ctrl [%08x] = %d", ctrl->id, ctrl->value);
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
-        if (!gspca_dev->present) {
-                ret = -ENODEV;
-                goto out;
-        }
         gspca_dev->usb_err = 0;
-        if (ctrls->set != NULL) {
-                ret = ctrls->set(gspca_dev, ctrl->value);
-                goto out;
-        }
+        if (ctrls->set != NULL)
+                return ctrls->set(gspca_dev, ctrl->value);
         if (gspca_ctrl != NULL) {
                 gspca_ctrl->val = ctrl->value;
                 if (ctrls->set_control != NULL
                  && gspca_dev->streaming)
                         ctrls->set_control(gspca_dev);
         }
-        ret = gspca_dev->usb_err;
-out:
-        mutex_unlock(&gspca_dev->usb_lock);
-        return ret;
+        return gspca_dev->usb_err;
 }
 
 static int vidioc_g_ctrl(struct file *file, void *priv,
@@ -1534,30 +1478,19 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
 {
         struct gspca_dev *gspca_dev = video_drvdata(file);
         const struct ctrl *ctrls;
-        int idx, ret;
+        int idx;
 
         idx = get_ctrl(gspca_dev, ctrl->id);
         if (idx < 0)
                 return -EINVAL;
         ctrls = &gspca_dev->sd_desc->ctrls[idx];
 
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
-        if (!gspca_dev->present) {
-                ret = -ENODEV;
-                goto out;
-        }
         gspca_dev->usb_err = 0;
-        if (ctrls->get != NULL) {
-                ret = ctrls->get(gspca_dev, &ctrl->value);
-                goto out;
-        }
+        if (ctrls->get != NULL)
+                return ctrls->get(gspca_dev, &ctrl->value);
         if (gspca_dev->cam.ctrls != NULL)
                 ctrl->value = gspca_dev->cam.ctrls[idx].val;
-        ret = 0;
-out:
-        mutex_unlock(&gspca_dev->usb_lock);
-        return ret;
+        return 0;
 }
 
 static int vidioc_querymenu(struct file *file, void *priv,
@@ -1640,10 +1573,8 @@ static int vidioc_reqbufs(struct file *file, void *priv,
         /* stop streaming */
         streaming = gspca_dev->streaming;
         if (streaming) {
-                mutex_lock(&gspca_dev->usb_lock);
                 gspca_dev->usb_err = 0;
                 gspca_stream_off(gspca_dev);
-                mutex_unlock(&gspca_dev->usb_lock);
 
                 /* Don't restart the stream when switching from read
                  * to mmap mode */
@@ -1748,13 +1679,8 @@ static int vidioc_streamoff(struct file *file, void *priv,
         }
 
         /* stop streaming */
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock)) {
-                ret = -ERESTARTSYS;
-                goto out;
-        }
         gspca_dev->usb_err = 0;
         gspca_stream_off(gspca_dev);
-        mutex_unlock(&gspca_dev->usb_lock);
         /* In case another thread is waiting in dqbuf */
         wake_up_interruptible(&gspca_dev->wq);
 
@@ -1772,38 +1698,22 @@ static int vidioc_g_jpegcomp(struct file *file, void *priv,
                         struct v4l2_jpegcompression *jpegcomp)
 {
         struct gspca_dev *gspca_dev = video_drvdata(file);
-        int ret;
 
         if (!gspca_dev->sd_desc->get_jcomp)
                 return -ENOTTY;
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
         gspca_dev->usb_err = 0;
-        if (gspca_dev->present)
-                ret = gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
-        else
-                ret = -ENODEV;
-        mutex_unlock(&gspca_dev->usb_lock);
-        return ret;
+        return gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
 }
 
 static int vidioc_s_jpegcomp(struct file *file, void *priv,
                         struct v4l2_jpegcompression *jpegcomp)
 {
         struct gspca_dev *gspca_dev = video_drvdata(file);
-        int ret;
 
         if (!gspca_dev->sd_desc->set_jcomp)
                 return -ENOTTY;
-        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                return -ERESTARTSYS;
         gspca_dev->usb_err = 0;
-        if (gspca_dev->present)
-                ret = gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
-        else
-                ret = -ENODEV;
-        mutex_unlock(&gspca_dev->usb_lock);
-        return ret;
+        return gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
 }
 
 static int vidioc_g_parm(struct file *filp, void *priv,
@@ -1814,21 +1724,10 @@ static int vidioc_g_parm(struct file *filp, void *priv,
         parm->parm.capture.readbuffers = gspca_dev->nbufread;
 
         if (gspca_dev->sd_desc->get_streamparm) {
-                int ret;
-
-                if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                        return -ERESTARTSYS;
-                if (gspca_dev->present) {
-                        gspca_dev->usb_err = 0;
-                        gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
-                        ret = gspca_dev->usb_err;
-                } else {
-                        ret = -ENODEV;
-                }
-                mutex_unlock(&gspca_dev->usb_lock);
-                return ret;
+                gspca_dev->usb_err = 0;
+                gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
+                return gspca_dev->usb_err;
         }
-
         return 0;
 }
 
@@ -1845,19 +1744,9 @@ static int vidioc_s_parm(struct file *filp, void *priv,
                 gspca_dev->nbufread = n;
 
         if (gspca_dev->sd_desc->set_streamparm) {
-                int ret;
-
-                if (mutex_lock_interruptible(&gspca_dev->usb_lock))
-                        return -ERESTARTSYS;
-                if (gspca_dev->present) {
-                        gspca_dev->usb_err = 0;
-                        gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
-                        ret = gspca_dev->usb_err;
-                } else {
-                        ret = -ENODEV;
-                }
-                mutex_unlock(&gspca_dev->usb_lock);
-                return ret;
+                gspca_dev->usb_err = 0;
+                gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
+                return gspca_dev->usb_err;
         }
 
         return 0;
@@ -1877,10 +1766,6 @@ static int dev_mmap(struct file *file, struct vm_area_struct *vma)
 
         if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                 return -ERESTARTSYS;
-        if (!gspca_dev->present) {
-                ret = -ENODEV;
-                goto out;
-        }
         if (gspca_dev->capt_file != file) {
                 ret = -EINVAL;
                 goto out;
@@ -2008,14 +1893,6 @@ static int vidioc_dqbuf(struct file *file, void *priv,
 
         gspca_dev->fr_o = (i + 1) % GSPCA_MAX_FRAMES;
 
-        if (gspca_dev->sd_desc->dq_callback) {
-                mutex_lock(&gspca_dev->usb_lock);
-                gspca_dev->usb_err = 0;
-                if (gspca_dev->present)
-                        gspca_dev->sd_desc->dq_callback(gspca_dev);
-                mutex_unlock(&gspca_dev->usb_lock);
-        }
-
         frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE;
         memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
         PDEBUG(D_FRAM, "dqbuf %d", j);
@@ -2032,6 +1909,15 @@ static int vidioc_dqbuf(struct file *file, void *priv,
         }
 out:
         mutex_unlock(&gspca_dev->queue_lock);
+
+        if (ret == 0 && gspca_dev->sd_desc->dq_callback) {
+                mutex_lock(&gspca_dev->usb_lock);
+                gspca_dev->usb_err = 0;
+                if (gspca_dev->present)
+                        gspca_dev->sd_desc->dq_callback(gspca_dev);
+                mutex_unlock(&gspca_dev->usb_lock);
+        }
+
         return ret;
 }
 
@@ -2103,6 +1989,10 @@ static int read_alloc(struct gspca_dev *gspca_dev,
         int i, ret;
 
         PDEBUG(D_STREAM, "read alloc");
+
+        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
+                return -ERESTARTSYS;
+
         if (gspca_dev->nframes == 0) {
                 struct v4l2_requestbuffers rb;
 
@@ -2113,7 +2003,7 @@ static int read_alloc(struct gspca_dev *gspca_dev,
                 ret = vidioc_reqbufs(file, gspca_dev, &rb);
                 if (ret != 0) {
                         PDEBUG(D_STREAM, "read reqbuf err %d", ret);
-                        return ret;
+                        goto out;
                 }
                 memset(&v4l2_buf, 0, sizeof v4l2_buf);
                 v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ -2123,16 +2013,17 @@ static int read_alloc(struct gspca_dev *gspca_dev,
                         ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
                         if (ret != 0) {
                                 PDEBUG(D_STREAM, "read qbuf err: %d", ret);
-                                return ret;
+                                goto out;
                         }
                 }
-                gspca_dev->memory = GSPCA_MEMORY_READ;
         }
 
         /* start streaming */
         ret = vidioc_streamon(file, gspca_dev, V4L2_BUF_TYPE_VIDEO_CAPTURE);
         if (ret != 0)
                 PDEBUG(D_STREAM, "read streamon err %d", ret);
+out:
+        mutex_unlock(&gspca_dev->usb_lock);
         return ret;
 }
 
@@ -2177,8 +2068,6 @@ static ssize_t dev_read(struct file *file, char __user *data,
         int n, ret, ret2;
 
         PDEBUG(D_FRAM, "read (%zd)", count);
-        if (!gspca_dev->present)
-                return -ENODEV;
         if (gspca_dev->memory == GSPCA_MEMORY_NO) { /* first time ? */
                 ret = read_alloc(gspca_dev, file);
                 if (ret != 0)
@@ -2280,7 +2169,7 @@ static const struct video_device gspca_template = {
         .name = "gspca main driver",
         .fops = &dev_fops,
         .ioctl_ops = &dev_ioctl_ops,
-        .release = gspca_release,
+        .release = video_device_release_empty, /* We use v4l2_dev.release */
 };
 
 /* initialize the controls */
@@ -2352,6 +2241,7 @@ int gspca_dev_probe2(struct usb_interface *intf,
                 }
         }
 
+        gspca_dev->v4l2_dev.release = gspca_release;
         ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
         if (ret)
                 goto out;
@@ -2366,6 +2256,7 @@ int gspca_dev_probe2(struct usb_interface *intf,
         gspca_dev->present = 1;
 
         mutex_init(&gspca_dev->usb_lock);
+        gspca_dev->vdev.lock = &gspca_dev->usb_lock;
         mutex_init(&gspca_dev->queue_lock);
         init_waitqueue_head(&gspca_dev->wq);
 
@@ -2388,6 +2279,15 @@ int gspca_dev_probe2(struct usb_interface *intf,
         if (ret)
                 goto out;
 
+        /*
+         * Don't take usb_lock for these ioctls. This improves latency if
+         * usb_lock is taken for a long time, e.g. when changing a control
+         * value, and a new frame is ready to be dequeued.
+         */
+        v4l2_dont_use_lock(&gspca_dev->vdev, VIDIOC_DQBUF);
+        v4l2_dont_use_lock(&gspca_dev->vdev, VIDIOC_QBUF);
+        v4l2_dont_use_lock(&gspca_dev->vdev, VIDIOC_QUERYBUF);
+
         /* init video stuff */
         ret = video_register_device(&gspca_dev->vdev,
                                   VFL_TYPE_GRABBER,
@@ -2455,11 +2355,13 @@ void gspca_disconnect(struct usb_interface *intf)
 
         PDEBUG(D_PROBE, "%s disconnect",
                 video_device_node_name(&gspca_dev->vdev));
+
         mutex_lock(&gspca_dev->usb_lock);
 
+        usb_set_intfdata(intf, NULL);
+        gspca_dev->dev = NULL;
         gspca_dev->present = 0;
         wake_up_interruptible(&gspca_dev->wq);
-
         destroy_urbs(gspca_dev);
 
 #if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
@@ -2471,18 +2373,13 @@ void gspca_disconnect(struct usb_interface *intf)
         }
 #endif
 
-        /* the device is freed at exit of this function */
-        gspca_dev->dev = NULL;
         v4l2_device_disconnect(&gspca_dev->v4l2_dev);
-        mutex_unlock(&gspca_dev->usb_lock);
+        video_unregister_device(&gspca_dev->vdev);
 
-        usb_set_intfdata(intf, NULL);
+        mutex_unlock(&gspca_dev->usb_lock);
 
-        /* release the device */
         /* (this will call gspca_release() immediately or on last close) */
-        video_unregister_device(&gspca_dev->vdev);
-
-/*      PDEBUG(D_PROBE, "disconnect complete"); */
+        v4l2_device_put(&gspca_dev->v4l2_dev);
 }
 EXPORT_SYMBOL(gspca_disconnect);
 
@@ -2493,17 +2390,16 @@ int gspca_suspend(struct usb_interface *intf, pm_message_t message)
 
         if (!gspca_dev->streaming)
                 return 0;
+        mutex_lock(&gspca_dev->usb_lock);
         gspca_dev->frozen = 1;          /* avoid urb error messages */
         if (gspca_dev->sd_desc->stopN)
                 gspca_dev->sd_desc->stopN(gspca_dev);
         destroy_urbs(gspca_dev);
         gspca_input_destroy_urb(gspca_dev);
         gspca_set_alt0(gspca_dev);
-        if (gspca_dev->sd_desc->stop0) {
-                mutex_lock(&gspca_dev->usb_lock);
+        if (gspca_dev->sd_desc->stop0)
                 gspca_dev->sd_desc->stop0(gspca_dev);
-                mutex_unlock(&gspca_dev->usb_lock);
-        }
+        mutex_unlock(&gspca_dev->usb_lock);
         return 0;
 }
 EXPORT_SYMBOL(gspca_suspend);
@@ -2513,6 +2409,7 @@ int gspca_resume(struct usb_interface *intf)
         struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
         int streaming, ret = 0;
 
+        mutex_lock(&gspca_dev->usb_lock);
         gspca_dev->frozen = 0;
         gspca_dev->sd_desc->init(gspca_dev);
         gspca_input_create_urb(gspca_dev);
@@ -2524,11 +2421,9 @@ int gspca_resume(struct usb_interface *intf)
         streaming = gspca_dev->streaming;
         gspca_dev->streaming = 0;
         v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
-        if (streaming) {
-                mutex_lock(&gspca_dev->queue_lock);
+        if (streaming)
                 ret = gspca_init_transfer(gspca_dev);
-                mutex_unlock(&gspca_dev->queue_lock);
-        }
+        mutex_unlock(&gspca_dev->usb_lock);
         return ret;
 }
 EXPORT_SYMBOL(gspca_resume);