2022-09-20 14:30:26

by Ricardo Ribalda

Subject: [PATCH v1 3/3] media: uvcvideo: Do power management granularly

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.

Reviewed-by: Tomasz Figa <[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 8d5002543e2c..b9642afabd9b 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -25,6 +25,46 @@

#include "uvcvideo.h"

+/* ------------------------------------------------------------------------
+ * UVC power management
+ */
+
+static int uvc_pm_get(struct uvc_streaming *stream)
+{
+ int ret = 0;
+
+ 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)
+{
+ 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
*/
@@ -249,6 +289,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
* developers test their webcams with the Linux driver as well as with
* the Windows driver).
*/
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
mutex_lock(&stream->mutex);
if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
probe->dwMaxVideoFrameSize =
@@ -257,6 +300,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
/* Probe the device. */
ret = uvc_probe_video(stream, probe);
mutex_unlock(&stream->mutex);
+ uvc_pm_put(stream);
if (ret < 0)
return ret;

@@ -468,7 +512,13 @@ 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;
@@ -559,36 +609,29 @@ 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);
+ /*
+ * If the uvc evdev exists we cannot suspend when the device
+ * is idle. Otherwise we will miss button actions.
+ */
+ if (stream->dev->input) {
+ int ret;
+
+ ret = uvc_pm_get(stream);
+ if (ret) {
kfree(handle);
return ret;
}
}

- stream->dev->users++;
- mutex_unlock(&stream->dev->lock);
-
v4l2_fh_init(&handle->vfh, &stream->vdev);
v4l2_fh_add(&handle->vfh);
handle->chain = stream->chain;
@@ -610,6 +653,12 @@ 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);
@@ -617,12 +666,6 @@ 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;
}

@@ -849,9 +892,17 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,

if (handle->is_streaming)
goto unlock;
+
+ ret = uvc_pm_get(stream);
+ if (ret)
+ goto unlock;
+
ret = uvc_queue_streamon(&stream->queue, type);
handle->is_streaming = !ret;

+ if (!handle->is_streaming)
+ uvc_pm_put(stream);
+
unlock:
mutex_unlock(&stream->mutex);

@@ -875,6 +926,9 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
ret = uvc_queue_streamoff(&stream->queue, type);
handle->is_streaming = !!ret;

+ if (!handle->is_streaming)
+ uvc_pm_put(stream);
+
unlock:
mutex_unlock(&stream->mutex);

@@ -928,6 +982,7 @@ 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;

@@ -941,9 +996,16 @@ 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;

@@ -956,6 +1018,7 @@ 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;

@@ -977,10 +1040,17 @@ 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;
@@ -991,8 +1061,15 @@ 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,
@@ -1000,10 +1077,15 @@ 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;

@@ -1049,6 +1131,7 @@ 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;
@@ -1073,22 +1156,30 @@ 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;
- return ret;
+ goto done;
}
}

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,
@@ -1097,6 +1188,7 @@ 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;

@@ -1104,9 +1196,15 @@ 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);
@@ -1114,16 +1212,20 @@ 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;
- return ret;
+ goto done;
}
}

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);
+
+done:
+ uvc_pm_put(stream);
+ return ret;
}

static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
@@ -1147,8 +1249,16 @@ 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;
+
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_query_v4l2_menu(chain, qm);
+ uvc_pm_put(stream);

- return uvc_query_v4l2_menu(chain, qm);
+ return ret;
}

static int uvc_ioctl_g_selection(struct file *file, void *fh,

--
b4 0.11.0-dev-d93f8

2022-10-25 13:05:00

by Laurent Pinchart

Subject: Re: [PATCH v1 3/3] media: uvcvideo: Do power management granularly

Hi Ricardo,

Thank you for the patch.

On Tue, Sep 20, 2022 at 04:09:52PM +0200, 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.
>
> Reviewed-by: Tomasz Figa <[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 8d5002543e2c..b9642afabd9b 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -25,6 +25,46 @@
>
> #include "uvcvideo.h"
>
> +/* ------------------------------------------------------------------------
> + * UVC power management
> + */
> +
> +static int uvc_pm_get(struct uvc_streaming *stream)
> +{
> + int ret = 0;

No need to initialize ret to 0.

> +
> + 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);

For devices that don't have a status endpoint, we will end up calling
uvc_status_start() and uvc_status_stop() around most ioctl calls (all
call sites of uvc_pm_get() and uvc_pm_put() below). uvc_status_start()
and uvc_status_stop() are no-op in that case, but conceptually I don't
think that's very nice. Could we instead keep the status start/stop
calls to open()/release() ?

If you don't mind, I'll give this a try and post a new version of the
patch, that should be faster than going through another review round.

> + 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)
> +{
> + 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
> */
> @@ -249,6 +289,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> * developers test their webcams with the Linux driver as well as with
> * the Windows driver).
> */
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> mutex_lock(&stream->mutex);
> if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
> probe->dwMaxVideoFrameSize =
> @@ -257,6 +300,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> /* Probe the device. */
> ret = uvc_probe_video(stream, probe);
> mutex_unlock(&stream->mutex);
> + uvc_pm_put(stream);
> if (ret < 0)
> return ret;
>
> @@ -468,7 +512,13 @@ 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;
> @@ -559,36 +609,29 @@ 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);
> + /*
> + * If the uvc evdev exists we cannot suspend when the device
> + * is idle. Otherwise we will miss button actions.
> + */
> + if (stream->dev->input) {
> + int ret;
> +
> + ret = uvc_pm_get(stream);
> + if (ret) {
> kfree(handle);
> return ret;
> }
> }
>
> - stream->dev->users++;
> - mutex_unlock(&stream->dev->lock);
> -
> v4l2_fh_init(&handle->vfh, &stream->vdev);
> v4l2_fh_add(&handle->vfh);
> handle->chain = stream->chain;
> @@ -610,6 +653,12 @@ 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);
> @@ -617,12 +666,6 @@ 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;
> }
>
> @@ -849,9 +892,17 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
>
> if (handle->is_streaming)
> goto unlock;
> +
> + ret = uvc_pm_get(stream);
> + if (ret)
> + goto unlock;
> +
> ret = uvc_queue_streamon(&stream->queue, type);
> handle->is_streaming = !ret;
>
> + if (!handle->is_streaming)
> + uvc_pm_put(stream);
> +
> unlock:
> mutex_unlock(&stream->mutex);
>
> @@ -875,6 +926,9 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
> ret = uvc_queue_streamoff(&stream->queue, type);
> handle->is_streaming = !!ret;
>
> + if (!handle->is_streaming)
> + uvc_pm_put(stream);
> +
> unlock:
> mutex_unlock(&stream->mutex);
>
> @@ -928,6 +982,7 @@ 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;
>
> @@ -941,9 +996,16 @@ 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;
>
> @@ -956,6 +1018,7 @@ 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;
>
> @@ -977,10 +1040,17 @@ 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;
> @@ -991,8 +1061,15 @@ 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,
> @@ -1000,10 +1077,15 @@ 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;
>
> @@ -1049,6 +1131,7 @@ 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;
> @@ -1073,22 +1156,30 @@ 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;
> - return ret;
> + goto done;
> }
> }
>
> 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,
> @@ -1097,6 +1188,7 @@ 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;
>
> @@ -1104,9 +1196,15 @@ 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);
> @@ -1114,16 +1212,20 @@ 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;
> - return ret;
> + goto done;
> }
> }
>
> 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);
> +
> +done:
> + uvc_pm_put(stream);
> + return ret;
> }
>
> static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> @@ -1147,8 +1249,16 @@ 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;
> +
> + ret = uvc_pm_get(stream);
> + if (ret)
> + return ret;
> + ret = uvc_query_v4l2_menu(chain, qm);
> + uvc_pm_put(stream);
>
> - return uvc_query_v4l2_menu(chain, qm);
> + return ret;
> }
>
> static int uvc_ioctl_g_selection(struct file *file, void *fh,
>

--
Regards,

Laurent Pinchart

2022-10-25 13:11:58

by Ricardo Ribalda

Subject: Re: [PATCH v1 3/3] media: uvcvideo: Do power management granularly

Hi Laurent

Thanks for the review!

On Tue, 25 Oct 2022 at 14:46, Laurent Pinchart
<[email protected]> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Tue, Sep 20, 2022 at 04:09:52PM +0200, 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.
> >
> > Reviewed-by: Tomasz Figa <[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 8d5002543e2c..b9642afabd9b 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -25,6 +25,46 @@
> >
> > #include "uvcvideo.h"
> >
> > +/* ------------------------------------------------------------------------
> > + * UVC power management
> > + */
> > +
> > +static int uvc_pm_get(struct uvc_streaming *stream)
> > +{
> > + int ret = 0;
>
> No need to initialize ret to 0.
>
> > +
> > + 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);
>
> For devices that don't have a status endpoint, we will end up calling
> uvc_status_start() and uvc_status_stop() around most ioctl calls (all
> call sites of uvc_pm_get() and uvc_pm_put() below). uvc_status_start()
> and uvc_status_stop() are no-op in that case, but conceptually I don't
> think that's very nice. Could we instead keep the status start/stop
> calls to open()/release() ?


I do not think that we can call uvc_status_start without calling
usb_autopm_get_interface()

We could add a flag on the device, and do something like:

if (!stream->dev->users && stream->dev->has_ststatus_enpoint)
ret = uvc_status_start(stream->dev, GFP_KERNEL);

But I am not sure what is cleaner...


>
> If you don't mind, I'll give this a try and post a new version of the
> patch, that should be faster than going through another review round.
>
> > + 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)
> > +{
> > + 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
> > */
> > @@ -249,6 +289,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> > * developers test their webcams with the Linux driver as well as with
> > * the Windows driver).
> > */
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > mutex_lock(&stream->mutex);
> > if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
> > probe->dwMaxVideoFrameSize =
> > @@ -257,6 +300,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> > /* Probe the device. */
> > ret = uvc_probe_video(stream, probe);
> > mutex_unlock(&stream->mutex);
> > + uvc_pm_put(stream);
> > if (ret < 0)
> > return ret;
> >
> > @@ -468,7 +512,13 @@ 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;
> > @@ -559,36 +609,29 @@ 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);
> > + /*
> > + * If the uvc evdev exists we cannot suspend when the device
> > + * is idle. Otherwise we will miss button actions.
> > + */
> > + if (stream->dev->input) {
> > + int ret;
> > +
> > + ret = uvc_pm_get(stream);
> > + if (ret) {
> > kfree(handle);
> > return ret;
> > }
> > }
> >
> > - stream->dev->users++;
> > - mutex_unlock(&stream->dev->lock);
> > -
> > v4l2_fh_init(&handle->vfh, &stream->vdev);
> > v4l2_fh_add(&handle->vfh);
> > handle->chain = stream->chain;
> > @@ -610,6 +653,12 @@ 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);
> > @@ -617,12 +666,6 @@ 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;
> > }
> >
> > @@ -849,9 +892,17 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> >
> > if (handle->is_streaming)
> > goto unlock;
> > +
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + goto unlock;
> > +
> > ret = uvc_queue_streamon(&stream->queue, type);
> > handle->is_streaming = !ret;
> >
> > + if (!handle->is_streaming)
> > + uvc_pm_put(stream);
> > +
> > unlock:
> > mutex_unlock(&stream->mutex);
> >
> > @@ -875,6 +926,9 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
> > ret = uvc_queue_streamoff(&stream->queue, type);
> > handle->is_streaming = !!ret;
> >
> > + if (!handle->is_streaming)
> > + uvc_pm_put(stream);
> > +
> > unlock:
> > mutex_unlock(&stream->mutex);
> >
> > @@ -928,6 +982,7 @@ 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;
> >
> > @@ -941,9 +996,16 @@ 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;
> >
> > @@ -956,6 +1018,7 @@ 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;
> >
> > @@ -977,10 +1040,17 @@ 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;
> > @@ -991,8 +1061,15 @@ 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,
> > @@ -1000,10 +1077,15 @@ 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;
> >
> > @@ -1049,6 +1131,7 @@ 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;
> > @@ -1073,22 +1156,30 @@ 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;
> > - return ret;
> > + goto done;
> > }
> > }
> >
> > 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,
> > @@ -1097,6 +1188,7 @@ 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;
> >
> > @@ -1104,9 +1196,15 @@ 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);
> > @@ -1114,16 +1212,20 @@ 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;
> > - return ret;
> > + goto done;
> > }
> > }
> >
> > 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);
> > +
> > +done:
> > + uvc_pm_put(stream);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> > @@ -1147,8 +1249,16 @@ 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;
> > +
> > + ret = uvc_pm_get(stream);
> > + if (ret)
> > + return ret;
> > + ret = uvc_query_v4l2_menu(chain, qm);
> > + uvc_pm_put(stream);
> >
> > - return uvc_query_v4l2_menu(chain, qm);
> > + return ret;
> > }
> >
> > static int uvc_ioctl_g_selection(struct file *file, void *fh,
> >
>
> --
> Regards,
>
> Laurent Pinchart



--
Ricardo Ribalda

2022-10-25 13:58:12

by Ricardo Ribalda

Subject: Re: [PATCH v1 3/3] media: uvcvideo: Do power management granularly

Hi again

On Tue, 25 Oct 2022 at 14:55, Ricardo Ribalda <[email protected]> wrote:
>
> Hi Laurent
>
> Thanks for the review!
>
> On Tue, 25 Oct 2022 at 14:46, Laurent Pinchart
> <[email protected]> wrote:
> >
> > Hi Ricardo,
> >
> > Thank you for the patch.
> >
> > On Tue, Sep 20, 2022 at 04:09:52PM +0200, 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.
> > >
> > > Reviewed-by: Tomasz Figa <[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 8d5002543e2c..b9642afabd9b 100644
> > > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > > @@ -25,6 +25,46 @@
> > >
> > > #include "uvcvideo.h"
> > >
> > > +/* ------------------------------------------------------------------------
> > > + * UVC power management
> > > + */
> > > +
> > > +static int uvc_pm_get(struct uvc_streaming *stream)
> > > +{
> > > + int ret = 0;
> >
> > No need to initialize ret to 0.
> >
> > > +
> > > + 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);
> >
> > For devices that don't have a status endpoint, we will end up calling
> > uvc_status_start() and uvc_status_stop() around most ioctl calls (all
> > call sites of uvc_pm_get() and uvc_pm_put() below). uvc_status_start()
> > and uvc_status_stop() are no-op in that case, but conceptually I don't
> > think that's very nice. Could we instead keep the status start/stop
> > calls to open()/release() ?
>
>
> I do not think that we can call uvc_status_start without calling
> usb_autopm_get_interface()
>
> We could add a flag on the device, and do something like:
>
> if (!stream->dev->users && stream->dev->has_ststatus_enpoint)
> ret = uvc_status_start(stream->dev, GFP_KERNEL);
>
> But I am not sure what is cleaner...
>

with the mentioned flag, we could make the locking a bit simpler on resume/start

Let me prepare something

Thanks!


>
> >
> > If you don't mind, I'll give this a try and post a new version of the
> > patch, that should be faster than going through another review round.
> >
> > > + 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)
> > > +{
> > > + 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
> > > */
> > > @@ -249,6 +289,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> > > * developers test their webcams with the Linux driver as well as with
> > > * the Windows driver).
> > > */
> > > + ret = uvc_pm_get(stream);
> > > + if (ret)
> > > + return ret;
> > > mutex_lock(&stream->mutex);
> > > if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
> > > probe->dwMaxVideoFrameSize =
> > > @@ -257,6 +300,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
> > > /* Probe the device. */
> > > ret = uvc_probe_video(stream, probe);
> > > mutex_unlock(&stream->mutex);
> > > + uvc_pm_put(stream);
> > > if (ret < 0)
> > > return ret;
> > >
> > > @@ -468,7 +512,13 @@ 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;
> > > @@ -559,36 +609,29 @@ 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);
> > > + /*
> > > + * If the uvc evdev exists we cannot suspend when the device
> > > + * is idle. Otherwise we will miss button actions.
> > > + */
> > > + if (stream->dev->input) {
> > > + int ret;
> > > +
> > > + ret = uvc_pm_get(stream);
> > > + if (ret) {
> > > kfree(handle);
> > > return ret;
> > > }
> > > }
> > >
> > > - stream->dev->users++;
> > > - mutex_unlock(&stream->dev->lock);
> > > -
> > > v4l2_fh_init(&handle->vfh, &stream->vdev);
> > > v4l2_fh_add(&handle->vfh);
> > > handle->chain = stream->chain;
> > > @@ -610,6 +653,12 @@ 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);
> > > @@ -617,12 +666,6 @@ 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;
> > > }
> > >
> > > @@ -849,9 +892,17 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
> > >
> > > if (handle->is_streaming)
> > > goto unlock;
> > > +
> > > + ret = uvc_pm_get(stream);
> > > + if (ret)
> > > + goto unlock;
> > > +
> > > ret = uvc_queue_streamon(&stream->queue, type);
> > > handle->is_streaming = !ret;
> > >
> > > + if (!handle->is_streaming)
> > > + uvc_pm_put(stream);
> > > +
> > > unlock:
> > > mutex_unlock(&stream->mutex);
> > >
> > > @@ -875,6 +926,9 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
> > > ret = uvc_queue_streamoff(&stream->queue, type);
> > > handle->is_streaming = !!ret;
> > >
> > > + if (!handle->is_streaming)
> > > + uvc_pm_put(stream);
> > > +
> > > unlock:
> > > mutex_unlock(&stream->mutex);
> > >
> > > @@ -928,6 +982,7 @@ 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;
> > >
> > > @@ -941,9 +996,16 @@ 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;
> > >
> > > @@ -956,6 +1018,7 @@ 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;
> > >
> > > @@ -977,10 +1040,17 @@ 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;
> > > @@ -991,8 +1061,15 @@ 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,
> > > @@ -1000,10 +1077,15 @@ 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;
> > >
> > > @@ -1049,6 +1131,7 @@ 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;
> > > @@ -1073,22 +1156,30 @@ 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;
> > > - return ret;
> > > + goto done;
> > > }
> > > }
> > >
> > > 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,
> > > @@ -1097,6 +1188,7 @@ 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;
> > >
> > > @@ -1104,9 +1196,15 @@ 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);
> > > @@ -1114,16 +1212,20 @@ 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;
> > > - return ret;
> > > + goto done;
> > > }
> > > }
> > >
> > > 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);
> > > +
> > > +done:
> > > + uvc_pm_put(stream);
> > > + return ret;
> > > }
> > >
> > > static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
> > > @@ -1147,8 +1249,16 @@ 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;
> > > +
> > > + ret = uvc_pm_get(stream);
> > > + if (ret)
> > > + return ret;
> > > + ret = uvc_query_v4l2_menu(chain, qm);
> > > + uvc_pm_put(stream);
> > >
> > > - return uvc_query_v4l2_menu(chain, qm);
> > > + return ret;
> > > }
> > >
> > > static int uvc_ioctl_g_selection(struct file *file, void *fh,
> > >
> >
> > --
> > Regards,
> >
> > Laurent Pinchart
>
>
>
> --
> Ricardo Ribalda



--
Ricardo Ribalda