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[media] pwc: Allow dqbuf / read to complete while waiting for controls

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Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans de Goede 2011-07-03 11:50:51 -03:00 committed by Mauro Carvalho Chehab
parent 6c9cac89c0
commit c11271349a
3 changed files with 38 additions and 4 deletions
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3
drivers/media/video/pwc/pwc-if.c
View file

@ -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);

36
drivers/media/video/pwc/pwc-v4l.c
View file

@ -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;
}

3
drivers/media/video/pwc/pwc.h
View file

@ -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 */