Instead of suspending/resume the USB device at open()/close(), do it
when the device is actually used.
This way we can reduce the power consumption when a service is holding
the video device and leaving it in an idle state.
To: Mauro Carvalho Chehab <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Laurent Pinchart <[email protected]>
Cc: Tomasz Figa <[email protected]>
Signed-off-by: Ricardo Ribalda <[email protected]>
---
Ricardo Ribalda (3):
media: uvcvideo: Only create input devs if hw supports it
media: uvcvideo: Refactor streamon/streamoff
media: uvcvideo: Do power management granularly
drivers/media/usb/uvc/uvc_status.c | 23 +++++
drivers/media/usb/uvc/uvc_v4l2.c | 193 ++++++++++++++++++++++++++++++-------
drivers/media/usb/uvc/uvcvideo.h | 1 +
3 files changed, 182 insertions(+), 35 deletions(-)
---
base-commit: 521a547ced6477c54b4b0cc206000406c221b4d6
change-id: 20220920-resend-powersave-5981719ed267
Best regards,
--
Ricardo Ribalda <[email protected]>
Add a new variable to handle the streaming state and handle the
streamoff errors, that were not handled before.
Suggested-by: Laurent Pinchart <[email protected]>
Signed-off-by: Ricardo Ribalda <[email protected]>
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 4cc3fa6b8c98..8d5002543e2c 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -840,13 +840,19 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
- int ret;
+ int ret = -EBUSY;
if (!uvc_has_privileges(handle))
return -EBUSY;
mutex_lock(&stream->mutex);
+
+ if (handle->is_streaming)
+ goto unlock;
ret = uvc_queue_streamon(&stream->queue, type);
+ handle->is_streaming = !ret;
+
+unlock:
mutex_unlock(&stream->mutex);
return ret;
@@ -857,15 +863,22 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
+ int ret = 0;
if (!uvc_has_privileges(handle))
return -EBUSY;
mutex_lock(&stream->mutex);
- uvc_queue_streamoff(&stream->queue, type);
+
+ if (!handle->is_streaming)
+ goto unlock;
+ ret = uvc_queue_streamoff(&stream->queue, type);
+ handle->is_streaming = !!ret;
+
+unlock:
mutex_unlock(&stream->mutex);
- return 0;
+ return ret;
}
static int uvc_ioctl_enum_input(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 24c911aeebce..caf74c87aaf1 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -725,6 +725,7 @@ enum uvc_handle_state {
struct uvc_fh {
struct v4l2_fh vfh;
+ bool is_streaming;
struct uvc_video_chain *chain;
struct uvc_streaming *stream;
enum uvc_handle_state state;
--
b4 0.11.0-dev-d93f8
Examine the stream headers to figure out if the device has a button and
can be used as an input.
Reviewed-by: Laurent Pinchart <[email protected]>
Signed-off-by: Ricardo Ribalda <[email protected]>
diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index 7518ffce22ed..cb90aff344bc 100644
--- a/drivers/media/usb/uvc/uvc_status.c
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -18,11 +18,34 @@
* Input device
*/
#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
+
+static bool uvc_input_has_button(struct uvc_device *dev)
+{
+ struct uvc_streaming *stream;
+
+ /*
+ * The device has button events if both bTriggerSupport and
+ * bTriggerUsage are one. Otherwise the camera button does not
+ * exist or is handled automatically by the camera without host
+ * driver or client application intervention.
+ */
+ list_for_each_entry(stream, &dev->streams, list) {
+ if (stream->header.bTriggerSupport == 1 &&
+ stream->header.bTriggerUsage == 1)
+ return true;
+ }
+
+ return false;
+}
+
static int uvc_input_init(struct uvc_device *dev)
{
struct input_dev *input;
int ret;
+ if (!uvc_input_has_button(dev))
+ return 0;
+
input = input_allocate_device();
if (input == NULL)
return -ENOMEM;
--
b4 0.11.0-dev-d93f8