diff mbox series

[v5,3/5] media: uvcvideo: Increase/decrease the PM counter per IOCTL

Message ID 20250303-uvc-granpower-ng-v5-3-a3dfbe29fe91@chromium.org
State New
Headers show
Series [v5,1/5] media: uvcvideo: Keep streaming state in the file handle | expand

Commit Message

Ricardo Ribalda March 3, 2025, 7:13 p.m. UTC 
Now we call uvc_pm_get/put from the device open/close. This low
level of granularity might leave the camera powered on in situations
where it is not needed.

Increase the granularity by increasing and decreasing the Power
Management counter per ioctl. There are two special cases where the
power management outlives the ioctl: async controls and streamon. Handle
those cases as well.

In a future patch, we will remove the uvc_pm_get/put from open/close.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 13 +++++++++++--
 drivers/media/usb/uvc/uvc_v4l2.c | 23 +++++++++++++++++++++--
 drivers/media/usb/uvc/uvcvideo.h |  1 +
 3 files changed, 33 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 4e58476d305e..47188c7f96c7 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1594,12 +1594,15 @@  static void uvc_ctrl_set_handle(struct uvc_fh *handle, struct uvc_control *ctrl,
 
 		if (ctrl->handle) {
 			WARN_ON(!ctrl->handle->pending_async_ctrls);
-			if (ctrl->handle->pending_async_ctrls)
+			if (ctrl->handle->pending_async_ctrls) {
 				ctrl->handle->pending_async_ctrls--;
+				uvc_pm_put(handle->chain->dev);
+			}
 		}
 
 		ctrl->handle = new_handle;
 		handle->pending_async_ctrls++;
+		uvc_pm_get(handle->chain->dev);
 		return;
 	}
 
@@ -1611,6 +1614,7 @@  static void uvc_ctrl_set_handle(struct uvc_fh *handle, struct uvc_control *ctrl,
 	if (WARN_ON(!handle->pending_async_ctrls))
 		return;
 	handle->pending_async_ctrls--;
+	uvc_pm_put(handle->chain->dev);
 }
 
 void uvc_ctrl_status_event(struct uvc_video_chain *chain,
@@ -2815,6 +2819,7 @@  int uvc_ctrl_init_device(struct uvc_device *dev)
 void uvc_ctrl_cleanup_fh(struct uvc_fh *handle)
 {
 	struct uvc_entity *entity;
+	int i;
 
 	guard(mutex)(&handle->chain->ctrl_mutex);
 
@@ -2829,7 +2834,11 @@  void uvc_ctrl_cleanup_fh(struct uvc_fh *handle)
 		}
 	}
 
-	WARN_ON(handle->pending_async_ctrls);
+	if (!WARN_ON(handle->pending_async_ctrls))
+		return;
+
+	for (i = 0; i < handle->pending_async_ctrls; i++)
+		uvc_pm_put(handle->stream->dev);
 }
 
 /*
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index de1e105f7263..1c9ac72be58a 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -691,6 +691,9 @@  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->dev);
+
 	/* Release the file handle. */
 	uvc_dismiss_privileges(handle);
 	v4l2_fh_del(&handle->vfh);
@@ -857,6 +860,7 @@  static int uvc_ioctl_streamon(struct file *file, void *fh,
 		return ret;
 
 	handle->is_streaming = true;
+	uvc_pm_get(stream->dev);
 
 	return 0;
 }
@@ -873,7 +877,10 @@  static int uvc_ioctl_streamoff(struct file *file, void *fh,
 	guard(mutex)(&stream->mutex);
 
 	uvc_queue_streamoff(&stream->queue, type);
-	handle->is_streaming = false;
+	if (handle->is_streaming) {
+		handle->is_streaming = false;
+		uvc_pm_put(stream->dev);
+	}
 
 	return 0;
 }
@@ -1410,6 +1417,8 @@  static long uvc_v4l2_compat_ioctl32(struct file *file,
 	void __user *up = compat_ptr(arg);
 	long ret;
 
+	guard(uvc_pm)(handle->stream->dev);
+
 	switch (cmd) {
 	case UVCIOC_CTRL_MAP32:
 		ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
@@ -1444,6 +1453,16 @@  static long uvc_v4l2_compat_ioctl32(struct file *file,
 }
 #endif
 
+static long uvc_v4l2_video_ioctl2(struct file *file,
+				  unsigned int cmd, unsigned long arg)
+{
+	struct uvc_fh *handle = file->private_data;
+
+	guard(uvc_pm)(handle->stream->dev);
+
+	return video_ioctl2(file, cmd, arg);
+}
+
 static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
 		    size_t count, loff_t *ppos)
 {
@@ -1529,7 +1548,7 @@  const struct v4l2_file_operations uvc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= uvc_v4l2_open,
 	.release	= uvc_v4l2_release,
-	.unlocked_ioctl	= video_ioctl2,
+	.unlocked_ioctl	= uvc_v4l2_video_ioctl2,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
 #endif
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index fbe3649c7cd6..eb8e374fa4c5 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -766,6 +766,7 @@  void uvc_status_put(struct uvc_device *dev);
 /* PM */
 int uvc_pm_get(struct uvc_device *dev);
 void uvc_pm_put(struct uvc_device *dev);
+DEFINE_GUARD(uvc_pm, struct uvc_device *, uvc_pm_get(_T), uvc_pm_put(_T))
 
 /* Controls */
 extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;