diff options
Diffstat (limited to 'drivers/media/video')
| -rw-r--r-- | drivers/media/video/pwc/pwc-if.c | 3 | ||||
| -rw-r--r-- | drivers/media/video/pwc/pwc-v4l.c | 36 | ||||
| -rw-r--r-- | drivers/media/video/pwc/pwc.h | 3 |
3 files changed, 38 insertions, 4 deletions
diff --git a/drivers/media/video/pwc/pwc-if.c b/drivers/media/video/pwc/pwc-if.c index 1d5a6db..fdf113f 100644 --- a/drivers/media/video/pwc/pwc-if.c +++ b/drivers/media/video/pwc/pwc-if.c @@ -1160,6 +1160,7 @@ static int usb_pwc_probe(struct usb_interface *intf, const struct usb_device_id pwc_construct(pdev); /* set min/max sizes correct */ mutex_init(&pdev->modlock); + mutex_init(&pdev->udevlock); spin_lock_init(&pdev->queued_bufs_lock); INIT_LIST_HEAD(&pdev->queued_bufs); @@ -1297,6 +1298,7 @@ static void usb_pwc_disconnect(struct usb_interface *intf) { struct pwc_device *pdev = usb_get_intfdata(intf); + mutex_lock(&pdev->udevlock); mutex_lock(&pdev->modlock); usb_set_intfdata(intf, NULL); @@ -1306,6 +1308,7 @@ static void usb_pwc_disconnect(struct usb_interface *intf) pdev->udev = NULL; mutex_unlock(&pdev->modlock); + mutex_unlock(&pdev->udevlock); pwc_remove_sysfs_files(pdev); video_unregister_device(&pdev->vdev); diff --git a/drivers/media/video/pwc/pwc-v4l.c b/drivers/media/video/pwc/pwc-v4l.c index 986dd5d..5376572 100644 --- a/drivers/media/video/pwc/pwc-v4l.c +++ b/drivers/media/video/pwc/pwc-v4l.c @@ -526,8 +526,24 @@ static int pwc_g_volatile_ctrl(struct v4l2_ctrl *ctrl) container_of(ctrl->handler, struct pwc_device, ctrl_handler); int ret = 0; - if (!pdev->udev) - return -ENODEV; + /* + * Sometimes it can take quite long for the pwc to complete usb control + * transfers, so release the modlock to give streaming by another + * process / thread the chance to continue with a dqbuf. + */ + mutex_unlock(&pdev->modlock); + + /* + * Take the udev-lock to protect against the disconnect handler + * completing and setting dev->udev to NULL underneath us. Other code + * does not need to do this since it is protected by the modlock. + */ + mutex_lock(&pdev->udevlock); + + if (!pdev->udev) { + ret = -ENODEV; + goto leave; + } switch (ctrl->id) { case V4L2_CID_AUTO_WHITE_BALANCE: @@ -590,6 +606,9 @@ static int pwc_g_volatile_ctrl(struct v4l2_ctrl *ctrl) if (ret) PWC_ERROR("g_ctrl %s error %d\n", ctrl->name, ret); +leave: + mutex_unlock(&pdev->udevlock); + mutex_lock(&pdev->modlock); return ret; } @@ -751,8 +770,14 @@ static int pwc_s_ctrl(struct v4l2_ctrl *ctrl) container_of(ctrl->handler, struct pwc_device, ctrl_handler); int ret = 0; - if (!pdev->udev) - return -ENODEV; + /* See the comments on locking in pwc_g_volatile_ctrl */ + mutex_unlock(&pdev->modlock); + mutex_lock(&pdev->udevlock); + + if (!pdev->udev) { + ret = -ENODEV; + goto leave; + } switch (ctrl->id) { case V4L2_CID_BRIGHTNESS: @@ -841,6 +866,9 @@ static int pwc_s_ctrl(struct v4l2_ctrl *ctrl) if (ret) PWC_ERROR("s_ctrl %s error %d\n", ctrl->name, ret); +leave: + mutex_unlock(&pdev->udevlock); + mutex_lock(&pdev->modlock); return ret; } diff --git a/drivers/media/video/pwc/pwc.h b/drivers/media/video/pwc/pwc.h index 601a549..e02dbf7 100644 --- a/drivers/media/video/pwc/pwc.h +++ b/drivers/media/video/pwc/pwc.h @@ -200,6 +200,9 @@ struct pwc_device /* Pointer to our usb_device, may be NULL after unplug */ struct usb_device *udev; + /* Protects the setting of udev to NULL by our disconnect handler */ + struct mutex udevlock; + /* type of cam (645, 646, 675, 680, 690, 720, 730, 740, 750) */ int type; int release; /* release number */ |
