diff mbox series

[v5,4/5] media: uvcvideo: Make power management granular

Message ID 20250303-uvc-granpower-ng-v5-4-a3dfbe29fe91@chromium.org
State Superseded
Headers show
Series media: uvcvideo: Implement Granular Power Saving | expand

Commit Message

Ricardo Ribalda March 3, 2025, 7:13 p.m. UTC 
Now that every ioctl takes care of their power management we can remove
the "global" power management.

Despite its size, this is a relatively big change. We hope that there
are no size effects of it. If there are some specific devices that
miss-behave, we can add a small quirk for them.

This patch introduces a behavioral change for the uvc "trigger" button.
Before the "trigger" button would work as long as userspace has opened
/dev/videoX. Now it only works when the camera is actually streaming. We
consider that this the most common (if not the only) usecase and
therefore we do not think of this as a regression.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 8 --------
 1 file changed, 8 deletions(-)

Comments

Laurent Pinchart March 27, 2025, 5:55 p.m. UTC | #1 
Hi Ricardo,

Thank you for the patch.

On Mon, Mar 03, 2025 at 07:13:41PM +0000, Ricardo Ribalda wrote:
> Now that every ioctl takes care of their power management we can remove
> the "global" power management.
> 
> Despite its size, this is a relatively big change. We hope that there
> are no size effects of it. If there are some specific devices that
> miss-behave, we can add a small quirk for them.
> 
> This patch introduces a behavioral change for the uvc "trigger" button.
> Before the "trigger" button would work as long as userspace has opened
> /dev/videoX. Now it only works when the camera is actually streaming. We
> consider that this the most common (if not the only) usecase and
> therefore we do not think of this as a regression.

We'll see :-)

> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 1c9ac72be58a..6af93e00b304 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -652,7 +652,6 @@ 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__);
> @@ -662,12 +661,6 @@ static int uvc_v4l2_open(struct file *file)
>  	if (!handle)
>  		return -ENOMEM;
>  
> -	ret = uvc_pm_get(stream->dev);
> -	if (ret) {
> -		kfree(handle);
> -		return ret;
> -	}
> -
>  	v4l2_fh_init(&handle->vfh, &stream->vdev);
>  	v4l2_fh_add(&handle->vfh);
>  	handle->chain = stream->chain;
> @@ -701,7 +694,6 @@ static int uvc_v4l2_release(struct file *file)
>  	kfree(handle);
>  	file->private_data = NULL;
>  
> -	uvc_pm_put(stream->dev);
>  	return 0;
>  }
>
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 1c9ac72be58a..6af93e00b304 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -652,7 +652,6 @@  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__);
@@ -662,12 +661,6 @@  static int uvc_v4l2_open(struct file *file)
 	if (!handle)
 		return -ENOMEM;
 
-	ret = uvc_pm_get(stream->dev);
-	if (ret) {
-		kfree(handle);
-		return ret;
-	}
-
 	v4l2_fh_init(&handle->vfh, &stream->vdev);
 	v4l2_fh_add(&handle->vfh);
 	handle->chain = stream->chain;
@@ -701,7 +694,6 @@  static int uvc_v4l2_release(struct file *file)
 	kfree(handle);
 	file->private_data = NULL;
 
-	uvc_pm_put(stream->dev);
 	return 0;
 }