Examine the stream headers to figure out if the device has a GPIO and
can be used as an input.
Signed-off-by: Ricardo Ribalda <[email protected]>
---
drivers/media/usb/uvc/uvc_status.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index 753c8226db70..3ef0b281ffc5 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 GPIO button event 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;
--
2.35.0.rc0.227.g00780c9af4-goog
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.
Signed-off-by: Ricardo Ribalda <[email protected]>
---
drivers/media/usb/uvc/uvc_v4l2.c | 199 +++++++++++++++++++++++++------
drivers/media/usb/uvc/uvcvideo.h | 1 +
2 files changed, 166 insertions(+), 34 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 711556d13d03..48217e47646f 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -25,6 +25,55 @@
#include "uvcvideo.h"
+/* ------------------------------------------------------------------------
+ * UVC power management
+ */
+
+static int uvc_pm_get(struct uvc_streaming *stream)
+{
+ int ret = 0;
+
+ if (!video_is_registered(&stream->vdev))
+ return -ENODEV;
+
+ /*
+ * We cannot hold dev->lock when calling autopm_get_interface.
+ */
+ ret = usb_autopm_get_interface(stream->dev->intf);
+ if (ret)
+ return ret;
+
+ mutex_lock(&stream->dev->lock);
+ if (!stream->dev->users)
+ ret = uvc_status_start(stream->dev, GFP_KERNEL);
+ if (!ret)
+ stream->dev->users++;
+ mutex_unlock(&stream->dev->lock);
+
+ if (ret)
+ usb_autopm_put_interface(stream->dev->intf);
+
+ return ret;
+}
+
+static void uvc_pm_put(struct uvc_streaming *stream)
+{
+ if (!video_is_registered(&stream->vdev))
+ return;
+
+ mutex_lock(&stream->dev->lock);
+ if (WARN_ON(!stream->dev->users)) {
+ mutex_unlock(&stream->dev->lock);
+ return;
+ }
+ stream->dev->users--;
+ if (!stream->dev->users)
+ uvc_status_stop(stream->dev);
+ mutex_unlock(&stream->dev->lock);
+
+ usb_autopm_put_interface(stream->dev->intf);
+}
+
/* ------------------------------------------------------------------------
* UVC ioctls
*/
@@ -251,8 +300,14 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
stream->ctrl.dwMaxVideoFrameSize;
/* Probe the device. */
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ mutex_unlock(&stream->mutex);
+ goto done;
+ }
ret = uvc_probe_video(stream, probe);
mutex_unlock(&stream->mutex);
+ uvc_pm_put(stream);
if (ret < 0)
goto done;
@@ -464,7 +519,13 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
}
/* Probe the device with the new settings. */
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ mutex_unlock(&stream->mutex);
+ return ret;
+ }
ret = uvc_probe_video(stream, &probe);
+ uvc_pm_put(stream);
if (ret < 0) {
mutex_unlock(&stream->mutex);
return ret;
@@ -555,36 +616,24 @@ static int uvc_v4l2_open(struct file *file)
{
struct uvc_streaming *stream;
struct uvc_fh *handle;
- int ret = 0;
stream = video_drvdata(file);
uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
- ret = usb_autopm_get_interface(stream->dev->intf);
- if (ret < 0)
- return ret;
-
/* Create the device handle. */
handle = kzalloc(sizeof(*handle), GFP_KERNEL);
- if (handle == NULL) {
- usb_autopm_put_interface(stream->dev->intf);
+ if (!handle)
return -ENOMEM;
- }
- mutex_lock(&stream->dev->lock);
- if (stream->dev->users == 0) {
- ret = uvc_status_start(stream->dev, GFP_KERNEL);
- if (ret < 0) {
- mutex_unlock(&stream->dev->lock);
- usb_autopm_put_interface(stream->dev->intf);
- kfree(handle);
- return ret;
- }
+ /*
+ * If the uvc evdev exists we cannot suspend when the device
+ * is idle. Otherwise we will miss button actions.
+ */
+ if (stream->dev->input && uvc_pm_get(stream)) {
+ kfree(handle);
+ return -ENODEV;
}
- stream->dev->users++;
- mutex_unlock(&stream->dev->lock);
-
v4l2_fh_init(&handle->vfh, &stream->vdev);
v4l2_fh_add(&handle->vfh);
handle->chain = stream->chain;
@@ -606,6 +655,12 @@ static int uvc_v4l2_release(struct file *file)
if (uvc_has_privileges(handle))
uvc_queue_release(&stream->queue);
+ if (handle->is_streaming)
+ uvc_pm_put(stream);
+
+ if (stream->dev->input)
+ uvc_pm_put(stream);
+
/* Release the file handle. */
uvc_dismiss_privileges(handle);
v4l2_fh_del(&handle->vfh);
@@ -613,12 +668,6 @@ static int uvc_v4l2_release(struct file *file)
kfree(handle);
file->private_data = NULL;
- mutex_lock(&stream->dev->lock);
- if (--stream->dev->users == 0)
- uvc_status_stop(stream->dev);
- mutex_unlock(&stream->dev->lock);
-
- usb_autopm_put_interface(stream->dev->intf);
return 0;
}
@@ -842,7 +891,21 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
return -EBUSY;
mutex_lock(&stream->mutex);
+ if (!handle->is_streaming) {
+ ret = uvc_pm_get(stream);
+ if (ret)
+ goto unlock;
+ }
+
ret = uvc_queue_streamon(&stream->queue, type);
+
+ if (ret && !handle->is_streaming)
+ uvc_pm_put(stream);
+
+ if (!ret)
+ handle->is_streaming = true;
+
+unlock:
mutex_unlock(&stream->mutex);
return ret;
@@ -859,6 +922,10 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
mutex_lock(&stream->mutex);
uvc_queue_streamoff(&stream->queue, type);
+ if (handle->is_streaming) {
+ handle->is_streaming = false;
+ uvc_pm_put(stream);
+ }
mutex_unlock(&stream->mutex);
return 0;
@@ -909,6 +976,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
u8 *buf;
int ret;
@@ -922,9 +990,16 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
if (!buf)
return -ENOMEM;
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ kfree(buf);
+ return ret;
+ }
+
ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
buf, 1);
+ uvc_pm_put(stream);
if (!ret)
*input = *buf - 1;
@@ -937,6 +1012,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
u8 *buf;
int ret;
@@ -958,10 +1034,17 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
if (!buf)
return -ENOMEM;
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ kfree(buf);
+ return ret;
+ }
+
*buf = input + 1;
ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
buf, 1);
+ uvc_pm_put(stream);
kfree(buf);
return ret;
@@ -972,8 +1055,15 @@ static int uvc_ioctl_queryctrl(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
+ int ret;
- return uvc_query_v4l2_ctrl(chain, qc);
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_query_v4l2_ctrl(chain, qc);
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
@@ -981,10 +1071,15 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
struct v4l2_queryctrl qc = { qec->id };
int ret;
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
ret = uvc_query_v4l2_ctrl(chain, &qc);
+ uvc_pm_put(stream);
if (ret)
return ret;
@@ -1030,6 +1125,7 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
struct v4l2_ext_control *ctrl = ctrls->controls;
unsigned int i;
int ret;
@@ -1054,22 +1150,30 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
return 0;
}
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
ret = uvc_ctrl_begin(chain);
- if (ret < 0)
+ if (ret < 0) {
+ uvc_pm_put(stream);
return ret;
+ }
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_get(chain, ctrl);
if (ret < 0) {
uvc_ctrl_rollback(handle);
ctrls->error_idx = i;
+ uvc_pm_put(stream);
return ret;
}
}
ctrls->error_idx = 0;
- return uvc_ctrl_rollback(handle);
+ ret = uvc_ctrl_rollback(handle);
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
@@ -1078,6 +1182,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
{
struct v4l2_ext_control *ctrl = ctrls->controls;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
unsigned int i;
int ret;
@@ -1085,9 +1190,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
if (ret < 0)
return ret;
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+
ret = uvc_ctrl_begin(chain);
- if (ret < 0)
+ if (ret < 0) {
+ uvc_pm_put(stream);
return ret;
+ }
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_set(handle, ctrl);
@@ -1095,6 +1206,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
uvc_ctrl_rollback(handle);
ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
ctrls->count : i;
+ uvc_pm_put(stream);
return ret;
}
}
@@ -1102,9 +1214,12 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
ctrls->error_idx = 0;
if (ioctl == VIDIOC_S_EXT_CTRLS)
- return uvc_ctrl_commit(handle, ctrls);
+ ret = uvc_ctrl_commit(handle, ctrls);
else
- return uvc_ctrl_rollback(handle);
+ ret = uvc_ctrl_rollback(handle);
+
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
@@ -1119,8 +1234,16 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
struct v4l2_ext_controls *ctrls)
{
struct uvc_fh *handle = fh;
+ struct uvc_streaming *stream = handle->stream;
+ int ret;
+
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
+ uvc_pm_put(stream);
- return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
+ return ret;
}
static int uvc_ioctl_querymenu(struct file *file, void *fh,
@@ -1128,8 +1251,16 @@ static int uvc_ioctl_querymenu(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
+ int ret;
- return uvc_query_v4l2_menu(chain, qm);
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_query_v4l2_menu(chain, qm);
+ uvc_pm_put(stream);
+
+ return ret;
}
static int uvc_ioctl_g_selection(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 143230b3275b..5958b2a54dab 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -720,6 +720,7 @@ 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;
--
2.35.0.rc0.227.g00780c9af4-goog
On Tue, Jan 25, 2022 at 4:07 AM Ricardo Ribalda <[email protected]> wrote:
>
> 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.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 199 +++++++++++++++++++++++++------
> drivers/media/usb/uvc/uvcvideo.h | 1 +
> 2 files changed, 166 insertions(+), 34 deletions(-)
Reviewed-by: Tomasz Figa <[email protected]>
Best regards,
Tomasz
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 711556d13d03..48217e47646f 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -25,6 +25,55 @@
>
> #include "uvcvideo.h"
>
> +/* ------------------------------------------------------------------------
> + * UVC power management
> + */
> +
> +static int uvc_pm_get(struct uvc_streaming *stream)
> +{
> + int ret = 0;
> +
> + if (!video_is_registered(&stream->vdev))
> + return -ENODEV;
> +
> + /*
> + * We cannot hold dev->lock when calling autopm_get_interface.
> + */
> + ret = usb_autopm_get_interface(stream->dev->intf);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&stream->dev->lock);
> + if (!stream->dev->users)
> + ret = uvc_status_start(stream->dev, GFP_KERNEL);
> + if (!ret)
> + stream->dev->users++;
> + mutex_unlock(&stream->dev->lock);
> +
> + if (ret)
> + usb_autopm_put_interface(stream->dev->intf);
> +
> + return ret;
> +}
> +
> +static void uvc_pm_put(struct uvc_streaming *stream)
> +{
> + if (!video_is_registered(&stream->vdev))
> + return;
> +
> + mutex_lock(&stream->dev->lock);
> + if (WARN_ON(!stream->dev->users)) {
> + mutex_unlock(&stream->dev->lock);
> + return;
> + }
> + stream->dev->users--;
> + if (!stream->dev->users)
> + uvc_status_stop(stream->dev);
> + mutex_unlock(&stream->dev->lock);
> +
> + usb_autopm_put_interface(stream->dev->intf);
> +}
> +
> /* ------------------------------------------------------------------------
> * UVC ioctls
> */
> @@ -251,8 +300,14 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> stream->ctrl.dwMaxVideoFrameSize;
>
> /* Probe the device. */
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + mutex_unlock(&stream->mutex);
> + goto done;
> + }
> ret = uvc_probe_video(stream, probe);
> mutex_unlock(&stream->mutex);
> + uvc_pm_put(stream);
> if (ret < 0)
> goto done;
>
> @@ -464,7 +519,13 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
> }
>
> /* Probe the device with the new settings. */
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + mutex_unlock(&stream->mutex);
> + return ret;
> + }
> ret = uvc_probe_video(stream, &probe);
> + uvc_pm_put(stream);
> if (ret < 0) {
> mutex_unlock(&stream->mutex);
> return ret;
> @@ -555,36 +616,24 @@ static int uvc_v4l2_open(struct file *file)
> {
> struct uvc_streaming *stream;
> struct uvc_fh *handle;
> - int ret = 0;
>
> stream = video_drvdata(file);
> uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
>
> - ret = usb_autopm_get_interface(stream->dev->intf);
> - if (ret < 0)
> - return ret;
> -
> /* Create the device handle. */
> handle = kzalloc(sizeof(*handle), GFP_KERNEL);
> - if (handle == NULL) {
> - usb_autopm_put_interface(stream->dev->intf);
> + if (!handle)
> return -ENOMEM;
> - }
>
> - mutex_lock(&stream->dev->lock);
> - if (stream->dev->users == 0) {
> - ret = uvc_status_start(stream->dev, GFP_KERNEL);
> - if (ret < 0) {
> - mutex_unlock(&stream->dev->lock);
> - usb_autopm_put_interface(stream->dev->intf);
> - kfree(handle);
> - return ret;
> - }
> + /*
> + * If the uvc evdev exists we cannot suspend when the device
> + * is idle. Otherwise we will miss button actions.
> + */
> + if (stream->dev->input && uvc_pm_get(stream)) {
> + kfree(handle);
> + return -ENODEV;
> }
>
> - stream->dev->users++;
> - mutex_unlock(&stream->dev->lock);
> -
> v4l2_fh_init(&handle->vfh, &stream->vdev);
> v4l2_fh_add(&handle->vfh);
> handle->chain = stream->chain;
> @@ -606,6 +655,12 @@ static int uvc_v4l2_release(struct file *file)
> if (uvc_has_privileges(handle))
> uvc_queue_release(&stream->queue);
>
> + if (handle->is_streaming)
> + uvc_pm_put(stream);
> +
> + if (stream->dev->input)
> + uvc_pm_put(stream);
> +
> /* Release the file handle. */
> uvc_dismiss_privileges(handle);
> v4l2_fh_del(&handle->vfh);
> @@ -613,12 +668,6 @@ static int uvc_v4l2_release(struct file *file)
> kfree(handle);
> file->private_data = NULL;
>
> - mutex_lock(&stream->dev->lock);
> - if (--stream->dev->users == 0)
> - uvc_status_stop(stream->dev);
> - mutex_unlock(&stream->dev->lock);
> -
> - usb_autopm_put_interface(stream->dev->intf);
> return 0;
> }
>
> @@ -842,7 +891,21 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> return -EBUSY;
>
> mutex_lock(&stream->mutex);
> + if (!handle->is_streaming) {
> + ret = uvc_pm_get(stream);
> + if (ret)
> + goto unlock;
> + }
> +
> ret = uvc_queue_streamon(&stream->queue, type);
> +
> + if (ret && !handle->is_streaming)
> + uvc_pm_put(stream);
> +
> + if (!ret)
> + handle->is_streaming = true;
> +
> +unlock:
> mutex_unlock(&stream->mutex);
>
> return ret;
> @@ -859,6 +922,10 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>
> mutex_lock(&stream->mutex);
> uvc_queue_streamoff(&stream->queue, type);
> + if (handle->is_streaming) {
> + handle->is_streaming = false;
> + uvc_pm_put(stream);
> + }
> mutex_unlock(&stream->mutex);
>
> return 0;
> @@ -909,6 +976,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> u8 *buf;
> int ret;
>
> @@ -922,9 +990,16 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> if (!buf)
> return -ENOMEM;
>
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + kfree(buf);
> + return ret;
> + }
> +
> ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
> chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> buf, 1);
> + uvc_pm_put(stream);
> if (!ret)
> *input = *buf - 1;
>
> @@ -937,6 +1012,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> u8 *buf;
> int ret;
>
> @@ -958,10 +1034,17 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> if (!buf)
> return -ENOMEM;
>
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + kfree(buf);
> + return ret;
> + }
> +
> *buf = input + 1;
> ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
> chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> buf, 1);
> + uvc_pm_put(stream);
> kfree(buf);
>
> return ret;
> @@ -972,8 +1055,15 @@ static int uvc_ioctl_queryctrl(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
>
> - return uvc_query_v4l2_ctrl(chain, qc);
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_query_v4l2_ctrl(chain, qc);
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> @@ -981,10 +1071,15 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> struct v4l2_queryctrl qc = { qec->id };
> int ret;
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> ret = uvc_query_v4l2_ctrl(chain, &qc);
> + uvc_pm_put(stream);
> if (ret)
> return ret;
>
> @@ -1030,6 +1125,7 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> struct v4l2_ext_control *ctrl = ctrls->controls;
> unsigned int i;
> int ret;
> @@ -1054,22 +1150,30 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> return 0;
> }
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> ret = uvc_ctrl_begin(chain);
> - if (ret < 0)
> + if (ret < 0) {
> + uvc_pm_put(stream);
> return ret;
> + }
>
> for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> ret = uvc_ctrl_get(chain, ctrl);
> if (ret < 0) {
> uvc_ctrl_rollback(handle);
> ctrls->error_idx = i;
> + uvc_pm_put(stream);
> return ret;
> }
> }
>
> ctrls->error_idx = 0;
>
> - return uvc_ctrl_rollback(handle);
> + ret = uvc_ctrl_rollback(handle);
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> @@ -1078,6 +1182,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> {
> struct v4l2_ext_control *ctrl = ctrls->controls;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> unsigned int i;
> int ret;
>
> @@ -1085,9 +1190,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> if (ret < 0)
> return ret;
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> +
> ret = uvc_ctrl_begin(chain);
> - if (ret < 0)
> + if (ret < 0) {
> + uvc_pm_put(stream);
> return ret;
> + }
>
> for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> ret = uvc_ctrl_set(handle, ctrl);
> @@ -1095,6 +1206,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> uvc_ctrl_rollback(handle);
> ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
> ctrls->count : i;
> + uvc_pm_put(stream);
> return ret;
> }
> }
> @@ -1102,9 +1214,12 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> ctrls->error_idx = 0;
>
> if (ioctl == VIDIOC_S_EXT_CTRLS)
> - return uvc_ctrl_commit(handle, ctrls);
> + ret = uvc_ctrl_commit(handle, ctrls);
> else
> - return uvc_ctrl_rollback(handle);
> + ret = uvc_ctrl_rollback(handle);
> +
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> @@ -1119,8 +1234,16 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
> struct v4l2_ext_controls *ctrls)
> {
> struct uvc_fh *handle = fh;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
> +
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> + uvc_pm_put(stream);
>
> - return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> + return ret;
> }
>
> static int uvc_ioctl_querymenu(struct file *file, void *fh,
> @@ -1128,8 +1251,16 @@ static int uvc_ioctl_querymenu(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
>
> - return uvc_query_v4l2_menu(chain, qm);
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_query_v4l2_menu(chain, qm);
> + uvc_pm_put(stream);
> +
> + return ret;
> }
>
> static int uvc_ioctl_g_selection(struct file *file, void *fh,
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 143230b3275b..5958b2a54dab 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -720,6 +720,7 @@ 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;
> --
> 2.35.0.rc0.227.g00780c9af4-goog
>
Hi Ricardo,
Thank you for the patch.
On Mon, Jan 24, 2022 at 08:00:12PM +0100, Ricardo Ribalda wrote:
> Examine the stream headers to figure out if the device has a GPIO and
> can be used as an input.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
> ---
> drivers/media/usb/uvc/uvc_status.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> index 753c8226db70..3ef0b281ffc5 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 GPIO button event if both bTriggerSupport and
The UVC specification doesn't talk about GPIOs but about buttons. With
s/GPIO button event/button events/ here and s/GPIO/button/ in the commit
message,
Reviewed-by: Laurent Pinchart <[email protected]>
> + * 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;
--
Regards,
Laurent Pinchart
Hi Ricardo,
Thank you for the patch.
On Mon, Jan 24, 2022 at 08:00:13PM +0100, Ricardo Ribalda wrote:
> 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.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 199 +++++++++++++++++++++++++------
> drivers/media/usb/uvc/uvcvideo.h | 1 +
> 2 files changed, 166 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 711556d13d03..48217e47646f 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -25,6 +25,55 @@
>
> #include "uvcvideo.h"
>
> +/* ------------------------------------------------------------------------
> + * UVC power management
> + */
> +
> +static int uvc_pm_get(struct uvc_streaming *stream)
> +{
> + int ret = 0;
> +
> + if (!video_is_registered(&stream->vdev))
> + return -ENODEV;
Can this happen ?
> +
> + /*
> + * We cannot hold dev->lock when calling autopm_get_interface.
> + */
Why is that ?
> + ret = usb_autopm_get_interface(stream->dev->intf);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&stream->dev->lock);
> + if (!stream->dev->users)
> + ret = uvc_status_start(stream->dev, GFP_KERNEL);
> + if (!ret)
> + stream->dev->users++;
> + mutex_unlock(&stream->dev->lock);
> +
> + if (ret)
> + usb_autopm_put_interface(stream->dev->intf);
Does this use autosuspend with a delay ?
> +
> + return ret;
> +}
> +
> +static void uvc_pm_put(struct uvc_streaming *stream)
> +{
> + if (!video_is_registered(&stream->vdev))
> + return;
If the device gets disconnected during streaming, we'll unregister the
video device. When uvc_pm_put() is called in uvc_v4l2_release(), it will
then return immediately. Won't this cause an unbalanced PM issue ?
> +
> + mutex_lock(&stream->dev->lock);
> + if (WARN_ON(!stream->dev->users)) {
> + mutex_unlock(&stream->dev->lock);
> + return;
> + }
> + stream->dev->users--;
> + if (!stream->dev->users)
> + uvc_status_stop(stream->dev);
> + mutex_unlock(&stream->dev->lock);
> +
> + usb_autopm_put_interface(stream->dev->intf);
> +}
> +
> /* ------------------------------------------------------------------------
> * UVC ioctls
> */
> @@ -251,8 +300,14 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> stream->ctrl.dwMaxVideoFrameSize;
>
> /* Probe the device. */
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + mutex_unlock(&stream->mutex);
> + goto done;
> + }
> ret = uvc_probe_video(stream, probe);
> mutex_unlock(&stream->mutex);
> + uvc_pm_put(stream);
uvc_pm_get() is called with the stream->mutex held, while uvc_pm_put()
isn't. Is there any specific reason ?
> if (ret < 0)
> goto done;
>
> @@ -464,7 +519,13 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
> }
>
> /* Probe the device with the new settings. */
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + mutex_unlock(&stream->mutex);
> + return ret;
> + }
> ret = uvc_probe_video(stream, &probe);
> + uvc_pm_put(stream);
> if (ret < 0) {
> mutex_unlock(&stream->mutex);
> return ret;
> @@ -555,36 +616,24 @@ static int uvc_v4l2_open(struct file *file)
> {
> struct uvc_streaming *stream;
> struct uvc_fh *handle;
> - int ret = 0;
>
> stream = video_drvdata(file);
> uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
>
> - ret = usb_autopm_get_interface(stream->dev->intf);
> - if (ret < 0)
> - return ret;
> -
> /* Create the device handle. */
> handle = kzalloc(sizeof(*handle), GFP_KERNEL);
> - if (handle == NULL) {
> - usb_autopm_put_interface(stream->dev->intf);
> + if (!handle)
> return -ENOMEM;
> - }
>
> - mutex_lock(&stream->dev->lock);
> - if (stream->dev->users == 0) {
> - ret = uvc_status_start(stream->dev, GFP_KERNEL);
> - if (ret < 0) {
> - mutex_unlock(&stream->dev->lock);
> - usb_autopm_put_interface(stream->dev->intf);
> - kfree(handle);
> - return ret;
> - }
> + /*
> + * If the uvc evdev exists we cannot suspend when the device
> + * is idle. Otherwise we will miss button actions.
> + */
> + if (stream->dev->input && uvc_pm_get(stream)) {
> + kfree(handle);
> + return -ENODEV;
> }
>
> - stream->dev->users++;
> - mutex_unlock(&stream->dev->lock);
> -
> v4l2_fh_init(&handle->vfh, &stream->vdev);
> v4l2_fh_add(&handle->vfh);
> handle->chain = stream->chain;
> @@ -606,6 +655,12 @@ static int uvc_v4l2_release(struct file *file)
> if (uvc_has_privileges(handle))
> uvc_queue_release(&stream->queue);
>
> + if (handle->is_streaming)
> + uvc_pm_put(stream);
> +
> + if (stream->dev->input)
> + uvc_pm_put(stream);
> +
> /* Release the file handle. */
> uvc_dismiss_privileges(handle);
> v4l2_fh_del(&handle->vfh);
> @@ -613,12 +668,6 @@ static int uvc_v4l2_release(struct file *file)
> kfree(handle);
> file->private_data = NULL;
>
> - mutex_lock(&stream->dev->lock);
> - if (--stream->dev->users == 0)
> - uvc_status_stop(stream->dev);
> - mutex_unlock(&stream->dev->lock);
> -
> - usb_autopm_put_interface(stream->dev->intf);
> return 0;
> }
>
> @@ -842,7 +891,21 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> return -EBUSY;
>
> mutex_lock(&stream->mutex);
> + if (!handle->is_streaming) {
> + ret = uvc_pm_get(stream);
> + if (ret)
> + goto unlock;
> + }
Is there any reason to continue if we're already streaming ? The other
option would be to call uvc_pm_get() unconditionally here.
> +
> ret = uvc_queue_streamon(&stream->queue, type);
> +
> + if (ret && !handle->is_streaming)
> + uvc_pm_put(stream);
> +
> + if (!ret)
> + handle->is_streaming = true;
> +
> +unlock:
> mutex_unlock(&stream->mutex);
>
> return ret;
> @@ -859,6 +922,10 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
>
> mutex_lock(&stream->mutex);
> uvc_queue_streamoff(&stream->queue, type);
Should we also handle errors from uvc_queue_streamoff() ? Maybe this
could be done in a separate patch that would also introduce
handle->is_streaming but without the PM. That would be easier to review.
> + if (handle->is_streaming) {
> + handle->is_streaming = false;
> + uvc_pm_put(stream);
> + }
> mutex_unlock(&stream->mutex);
>
> return 0;
> @@ -909,6 +976,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> u8 *buf;
> int ret;
>
> @@ -922,9 +990,16 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> if (!buf)
> return -ENOMEM;
>
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + kfree(buf);
> + return ret;
> + }
> +
> ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
> chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> buf, 1);
> + uvc_pm_put(stream);
> if (!ret)
> *input = *buf - 1;
>
> @@ -937,6 +1012,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> u8 *buf;
> int ret;
>
> @@ -958,10 +1034,17 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> if (!buf)
> return -ENOMEM;
>
> + ret = uvc_pm_get(stream);
> + if (ret) {
> + kfree(buf);
> + return ret;
> + }
> +
> *buf = input + 1;
> ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
> chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> buf, 1);
> + uvc_pm_put(stream);
> kfree(buf);
>
> return ret;
> @@ -972,8 +1055,15 @@ static int uvc_ioctl_queryctrl(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
>
> - return uvc_query_v4l2_ctrl(chain, qc);
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_query_v4l2_ctrl(chain, qc);
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> @@ -981,10 +1071,15 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> struct v4l2_queryctrl qc = { qec->id };
> int ret;
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> ret = uvc_query_v4l2_ctrl(chain, &qc);
> + uvc_pm_put(stream);
> if (ret)
> return ret;
>
> @@ -1030,6 +1125,7 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> struct v4l2_ext_control *ctrl = ctrls->controls;
> unsigned int i;
> int ret;
> @@ -1054,22 +1150,30 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> return 0;
> }
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> ret = uvc_ctrl_begin(chain);
> - if (ret < 0)
> + if (ret < 0) {
> + uvc_pm_put(stream);
> return ret;
I'd prefer a "goto done" style.
> + }
>
> for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> ret = uvc_ctrl_get(chain, ctrl);
> if (ret < 0) {
> uvc_ctrl_rollback(handle);
> ctrls->error_idx = i;
> + uvc_pm_put(stream);
> return ret;
> }
> }
>
> ctrls->error_idx = 0;
>
> - return uvc_ctrl_rollback(handle);
> + ret = uvc_ctrl_rollback(handle);
done:
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> @@ -1078,6 +1182,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> {
> struct v4l2_ext_control *ctrl = ctrls->controls;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> unsigned int i;
> int ret;
>
> @@ -1085,9 +1190,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> if (ret < 0)
> return ret;
>
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> +
> ret = uvc_ctrl_begin(chain);
> - if (ret < 0)
> + if (ret < 0) {
> + uvc_pm_put(stream);
> return ret;
Same in this function.
> + }
>
> for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> ret = uvc_ctrl_set(handle, ctrl);
> @@ -1095,6 +1206,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> uvc_ctrl_rollback(handle);
> ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
> ctrls->count : i;
> + uvc_pm_put(stream);
> return ret;
> }
> }
> @@ -1102,9 +1214,12 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> ctrls->error_idx = 0;
>
> if (ioctl == VIDIOC_S_EXT_CTRLS)
> - return uvc_ctrl_commit(handle, ctrls);
> + ret = uvc_ctrl_commit(handle, ctrls);
> else
> - return uvc_ctrl_rollback(handle);
> + ret = uvc_ctrl_rollback(handle);
> +
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> @@ -1119,8 +1234,16 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
> struct v4l2_ext_controls *ctrls)
> {
> struct uvc_fh *handle = fh;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
> +
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> + uvc_pm_put(stream);
uvc_ioctl_s_try_ext_ctrls() handles PM, do you need it here too ? The
other option is to drop it from uvc_ioctl_s_try_ext_ctrls(), keep it
here and add it to uvc_ioctl_try_ext_ctrls(). That would result in a
smaller diff, and standardize on handling PM as close as possible to the
top of the call stack, so it could be better.
>
> - return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> + return ret;
> }
>
> static int uvc_ioctl_querymenu(struct file *file, void *fh,
> @@ -1128,8 +1251,16 @@ static int uvc_ioctl_querymenu(struct file *file, void *fh,
> {
> struct uvc_fh *handle = fh;
> struct uvc_video_chain *chain = handle->chain;
> + struct uvc_streaming *stream = handle->stream;
> + int ret;
>
> - return uvc_query_v4l2_menu(chain, qm);
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_query_v4l2_menu(chain, qm);
> + uvc_pm_put(stream);
> +
> + return ret;
> }
>
> static int uvc_ioctl_g_selection(struct file *file, void *fh,
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 143230b3275b..5958b2a54dab 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -720,6 +720,7 @@ 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;
--
Regards,
Laurent Pinchart
Hi Laurent
Thanks for the review! :)
I have uploaded v5 with all the changes, (please ignore v4 ;))
Best regards!
On Thu, 3 Feb 2022 at 04:53, Laurent Pinchart
<[email protected]> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Mon, Jan 24, 2022 at 08:00:13PM +0100, Ricardo Ribalda wrote:
> > 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.
> >
> > Signed-off-by: Ricardo Ribalda <[email protected]>
> > ---
> > drivers/media/usb/uvc/uvc_v4l2.c | 199 +++++++++++++++++++++++++------
> > drivers/media/usb/uvc/uvcvideo.h | 1 +
> > 2 files changed, 166 insertions(+), 34 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> > index 711556d13d03..48217e47646f 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -25,6 +25,55 @@
> >
> > #include "uvcvideo.h"
> >
> > +/* ------------------------------------------------------------------------
> > + * UVC power management
> > + */
> > +
> > +static int uvc_pm_get(struct uvc_streaming *stream)
> > +{
> > + int ret = 0;
> > +
> > + if (!video_is_registered(&stream->vdev))
> > + return -ENODEV;
>
> Can this happen ?
It is some leftovers from code backported from our kernel sorry.
https://lkml.org/lkml/2020/8/30/183
>
> > +
> > + /*
> > + * We cannot hold dev->lock when calling autopm_get_interface.
> > + */
>
> Why is that ?
Because _uvc_resume takes the same lock.
>
> > + ret = usb_autopm_get_interface(stream->dev->intf);
> > + if (ret)
> > + return ret;
> > +
> > + mutex_lock(&stream->dev->lock);
> > + if (!stream->dev->users)
> > + ret = uvc_status_start(stream->dev, GFP_KERNEL);
> > + if (!ret)
> > + stream->dev->users++;
> > + mutex_unlock(&stream->dev->lock);
> > +
> > + if (ret)
> > + usb_autopm_put_interface(stream->dev->intf);
>
> Does this use autosuspend with a delay ?
I believe the default autosuspend is 2 sec.
https://www.kernel.org/doc/Documentation/usb/power-management.txt
>
> > +
> > + return ret;
> > +}
> > +
> > +static void uvc_pm_put(struct uvc_streaming *stream)
> > +{
> > + if (!video_is_registered(&stream->vdev))
> > + return;
>
> If the device gets disconnected during streaming, we'll unregister the
> video device. When uvc_pm_put() is called in uvc_v4l2_release(), it will
> then return immediately. Won't this cause an unbalanced PM issue ?
I just removed it thanks :)
>
> > +
> > + mutex_lock(&stream->dev->lock);
> > + if (WARN_ON(!stream->dev->users)) {
> > + mutex_unlock(&stream->dev->lock);
> > + return;
> > + }
> > + stream->dev->users--;
> > + if (!stream->dev->users)
> > + uvc_status_stop(stream->dev);
> > + mutex_unlock(&stream->dev->lock);
> > +
> > + usb_autopm_put_interface(stream->dev->intf);
> > +}
> > +
> > /* ------------------------------------------------------------------------
> > * UVC ioctls
> > */
> > @@ -251,8 +300,14 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> > stream->ctrl.dwMaxVideoFrameSize;
> >
> > /* Probe the device. */
> > + ret = uvc_pm_get(stream);
> > + if (ret) {
> > + mutex_unlock(&stream->mutex);
> > + goto done;
> > + }
> > ret = uvc_probe_video(stream, probe);
> > mutex_unlock(&stream->mutex);
> > + uvc_pm_put(stream);
>
> uvc_pm_get() is called with the stream->mutex held, while uvc_pm_put()
> isn't. Is there any specific reason ?
Good catch, moving get outside of the lock
>
> > if (ret < 0)
> > goto done;
> >
> > @@ -464,7 +519,13 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
> > }
> >
> > /* Probe the device with the new settings. */
> > + ret = uvc_pm_get(stream);
> > + if (ret) {
> > + mutex_unlock(&stream->mutex);
> > + return ret;
> > + }
> > ret = uvc_probe_video(stream, &probe);
> > + uvc_pm_put(stream);
> > if (ret < 0) {
> > mutex_unlock(&stream->mutex);
> > return ret;
> > @@ -555,36 +616,24 @@ static int uvc_v4l2_open(struct file *file)
> > {
> > struct uvc_streaming *stream;
> > struct uvc_fh *handle;
> > - int ret = 0;
> >
> > stream = video_drvdata(file);
> > uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
> >
> > - ret = usb_autopm_get_interface(stream->dev->intf);
> > - if (ret < 0)
> > - return ret;
> > -
> > /* Create the device handle. */
> > handle = kzalloc(sizeof(*handle), GFP_KERNEL);
> > - if (handle == NULL) {
> > - usb_autopm_put_interface(stream->dev->intf);
> > + if (!handle)
> > return -ENOMEM;
> > - }
> >
> > - mutex_lock(&stream->dev->lock);
> > - if (stream->dev->users == 0) {
> > - ret = uvc_status_start(stream->dev, GFP_KERNEL);
> > - if (ret < 0) {
> > - mutex_unlock(&stream->dev->lock);
> > - usb_autopm_put_interface(stream->dev->intf);
> > - kfree(handle);
> > - return ret;
> > - }
> > + /*
> > + * If the uvc evdev exists we cannot suspend when the device
> > + * is idle. Otherwise we will miss button actions.
> > + */
> > + if (stream->dev->input && uvc_pm_get(stream)) {
> > + kfree(handle);
> > + return -ENODEV;
> > }
> >
> > - stream->dev->users++;
> > - mutex_unlock(&stream->dev->lock);
> > -
> > v4l2_fh_init(&handle->vfh, &stream->vdev);
> > v4l2_fh_add(&handle->vfh);
> > handle->chain = stream->chain;
> > @@ -606,6 +655,12 @@ static int uvc_v4l2_release(struct file *file)
> > if (uvc_has_privileges(handle))
> > uvc_queue_release(&stream->queue);
> >
> > + if (handle->is_streaming)
> > + uvc_pm_put(stream);
> > +
> > + if (stream->dev->input)
> > + uvc_pm_put(stream);
> > +
> > /* Release the file handle. */
> > uvc_dismiss_privileges(handle);
> > v4l2_fh_del(&handle->vfh);
> > @@ -613,12 +668,6 @@ static int uvc_v4l2_release(struct file *file)
> > kfree(handle);
> > file->private_data = NULL;
> >
> > - mutex_lock(&stream->dev->lock);
> > - if (--stream->dev->users == 0)
> > - uvc_status_stop(stream->dev);
> > - mutex_unlock(&stream->dev->lock);
> > -
> > - usb_autopm_put_interface(stream->dev->intf);
> > return 0;
> > }
> >
> > @@ -842,7 +891,21 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> > return -EBUSY;
> >
> > mutex_lock(&stream->mutex);
> > + if (!handle->is_streaming) {
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + goto unlock;
> > + }
>
> Is there any reason to continue if we're already streaming ? The other
> option would be to call uvc_pm_get() unconditionally here.
I would rather handle it with the next suggestion ;)
>
> > +
> > ret = uvc_queue_streamon(&stream->queue, type);
> > +
> > + if (ret && !handle->is_streaming)
> > + uvc_pm_put(stream);
> > +
> > + if (!ret)
> > + handle->is_streaming = true;
> > +
> > +unlock:
> > mutex_unlock(&stream->mutex);
> >
> > return ret;
> > @@ -859,6 +922,10 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
> >
> > mutex_lock(&stream->mutex);
> > uvc_queue_streamoff(&stream->queue, type);
>
> Should we also handle errors from uvc_queue_streamoff() ? Maybe this
> could be done in a separate patch that would also introduce
> handle->is_streaming but without the PM. That would be easier to review.
Done!
>
> > + if (handle->is_streaming) {
> > + handle->is_streaming = false;
> > + uvc_pm_put(stream);
> > + }
> > mutex_unlock(&stream->mutex);
> >
> > return 0;
> > @@ -909,6 +976,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > u8 *buf;
> > int ret;
> >
> > @@ -922,9 +990,16 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
> > if (!buf)
> > return -ENOMEM;
> >
> > + ret = uvc_pm_get(stream);
> > + if (ret) {
> > + kfree(buf);
> > + return ret;
> > + }
> > +
> > ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
> > chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> > buf, 1);
> > + uvc_pm_put(stream);
> > if (!ret)
> > *input = *buf - 1;
> >
> > @@ -937,6 +1012,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > u8 *buf;
> > int ret;
> >
> > @@ -958,10 +1034,17 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
> > if (!buf)
> > return -ENOMEM;
> >
> > + ret = uvc_pm_get(stream);
> > + if (ret) {
> > + kfree(buf);
> > + return ret;
> > + }
> > +
> > *buf = input + 1;
> > ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
> > chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
> > buf, 1);
> > + uvc_pm_put(stream);
> > kfree(buf);
> >
> > return ret;
> > @@ -972,8 +1055,15 @@ static int uvc_ioctl_queryctrl(struct file *file, void *fh,
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > + int ret;
> >
> > - return uvc_query_v4l2_ctrl(chain, qc);
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > + ret = uvc_query_v4l2_ctrl(chain, qc);
> > + uvc_pm_put(stream);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> > @@ -981,10 +1071,15 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > struct v4l2_queryctrl qc = { qec->id };
> > int ret;
> >
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > ret = uvc_query_v4l2_ctrl(chain, &qc);
> > + uvc_pm_put(stream);
> > if (ret)
> > return ret;
> >
> > @@ -1030,6 +1125,7 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > struct v4l2_ext_control *ctrl = ctrls->controls;
> > unsigned int i;
> > int ret;
> > @@ -1054,22 +1150,30 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> > return 0;
> > }
> >
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > ret = uvc_ctrl_begin(chain);
> > - if (ret < 0)
> > + if (ret < 0) {
> > + uvc_pm_put(stream);
> > return ret;
>
> I'd prefer a "goto done" style.
>
> > + }
> >
> > for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> > ret = uvc_ctrl_get(chain, ctrl);
> > if (ret < 0) {
> > uvc_ctrl_rollback(handle);
> > ctrls->error_idx = i;
> > + uvc_pm_put(stream);
> > return ret;
> > }
> > }
> >
> > ctrls->error_idx = 0;
> >
> > - return uvc_ctrl_rollback(handle);
> > + ret = uvc_ctrl_rollback(handle);
>
> done:
>
> > + uvc_pm_put(stream);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> > @@ -1078,6 +1182,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> > {
> > struct v4l2_ext_control *ctrl = ctrls->controls;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > unsigned int i;
> > int ret;
> >
> > @@ -1085,9 +1190,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> > if (ret < 0)
> > return ret;
> >
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > +
> > ret = uvc_ctrl_begin(chain);
> > - if (ret < 0)
> > + if (ret < 0) {
> > + uvc_pm_put(stream);
> > return ret;
>
> Same in this function.
>
> > + }
> >
> > for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> > ret = uvc_ctrl_set(handle, ctrl);
> > @@ -1095,6 +1206,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> > uvc_ctrl_rollback(handle);
> > ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
> > ctrls->count : i;
> > + uvc_pm_put(stream);
> > return ret;
> > }
> > }
> > @@ -1102,9 +1214,12 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
> > ctrls->error_idx = 0;
> >
> > if (ioctl == VIDIOC_S_EXT_CTRLS)
> > - return uvc_ctrl_commit(handle, ctrls);
> > + ret = uvc_ctrl_commit(handle, ctrls);
> > else
> > - return uvc_ctrl_rollback(handle);
> > + ret = uvc_ctrl_rollback(handle);
> > +
> > + uvc_pm_put(stream);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> > @@ -1119,8 +1234,16 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
> > struct v4l2_ext_controls *ctrls)
> > {
> > struct uvc_fh *handle = fh;
> > + struct uvc_streaming *stream = handle->stream;
> > + int ret;
> > +
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > + ret = uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> > + uvc_pm_put(stream);
>
> uvc_ioctl_s_try_ext_ctrls() handles PM, do you need it here too ? The
> other option is to drop it from uvc_ioctl_s_try_ext_ctrls(), keep it
> here and add it to uvc_ioctl_try_ext_ctrls(). That would result in a
> smaller diff, and standardize on handling PM as close as possible to the
> top of the call stack, so it could be better.
>
> >
> > - return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_querymenu(struct file *file, void *fh,
> > @@ -1128,8 +1251,16 @@ static int uvc_ioctl_querymenu(struct file *file, void *fh,
> > {
> > struct uvc_fh *handle = fh;
> > struct uvc_video_chain *chain = handle->chain;
> > + struct uvc_streaming *stream = handle->stream;
> > + int ret;
> >
> > - return uvc_query_v4l2_menu(chain, qm);
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > + ret = uvc_query_v4l2_menu(chain, qm);
> > + uvc_pm_put(stream);
> > +
> > + return ret;
> > }
> >
> > static int uvc_ioctl_g_selection(struct file *file, void *fh,
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index 143230b3275b..5958b2a54dab 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -720,6 +720,7 @@ 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;
>
> --
> Regards,
>
> Laurent Pinchart
--
Ricardo Ribalda