linux-kernel - [PATCH 4/9] media: uvcvideo: Move usb_autopm_(get|put)_interface to status

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Message-Id: <20241126-uvc-granpower-ng-v1-4-6312bf26549c@chromium.org>
Date: Tue, 26 Nov 2024 16:18:54 +0000
From: Ricardo Ribalda <ribalda@...omium.org>
To: Laurent Pinchart <laurent.pinchart@...asonboard.com>, 
 Hans de Goede <hdegoede@...hat.com>, 
 Mauro Carvalho Chehab <mchehab@...nel.org>, 
 Guennadi Liakhovetski <guennadi.liakhovetski@...el.com>
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Mauro Carvalho Chehab <mchehab+samsung@...nel.org>, 
 Ricardo Ribalda <ribalda@...omium.org>
Subject: [PATCH 4/9] media: uvcvideo: Move usb_autopm_(get|put)_interface
 to status_get

Right now PM operations are always called at the same locations as
uvc_status_(get|put).

Combine them into uvc_status_(get|put). This simplifies the current
code and future PM changes in the driver.

Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
---
 drivers/media/usb/uvc/uvc_status.c | 38 +++++++++++++++++++++++++++++++++-----
 drivers/media/usb/uvc/uvc_v4l2.c   | 11 +----------
 2 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index 06c867510c8f..f7531ed0fa84 100644
--- a/drivers/media/usb/uvc/uvc_status.c
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -378,7 +378,7 @@ void uvc_status_suspend(struct uvc_device *dev)
 		uvc_status_stop(dev);
 }
 
-int uvc_status_get(struct uvc_device *dev)
+static int _uvc_status_get(struct uvc_device *dev)
 {
 	int ret;
 
@@ -395,13 +395,41 @@ int uvc_status_get(struct uvc_device *dev)
 	return 0;
 }
 
-void uvc_status_put(struct uvc_device *dev)
+int uvc_status_get(struct uvc_device *dev)
+{
+	int ret;
+
+	ret = usb_autopm_get_interface(dev->intf);
+	if (ret)
+		return ret;
+
+	ret = _uvc_status_get(dev);
+
+	if (ret)
+		usb_autopm_put_interface(dev->intf);
+
+	return ret;
+}
+
+static int _uvc_status_put(struct uvc_device *dev)
 {
 	guard(mutex)(&dev->status_lock);
 
 	if (dev->status_users == 1)
 		uvc_status_stop(dev);
-	WARN_ON(!dev->status_users);
-	if (dev->status_users)
-		dev->status_users--;
+
+	if (WARN_ON(!dev->status_users))
+		return -EIO;
+
+	dev->status_users--;
+	return 0;
+}
+
+void uvc_status_put(struct uvc_device *dev)
+{
+	int ret;
+
+	ret = _uvc_status_put(dev);
+	if (!ret)
+		usb_autopm_put_interface(dev->intf);
 }
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 712a531e52f9..1d4db712137e 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -617,20 +617,13 @@ static int uvc_v4l2_open(struct file *file)
 	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;
-	}
 
 	ret = uvc_status_get(stream->dev);
 	if (ret) {
-		usb_autopm_put_interface(stream->dev->intf);
 		kfree(handle);
 		return ret;
 	}
@@ -666,8 +659,6 @@ static int uvc_v4l2_release(struct file *file)
 	file->private_data = NULL;
 
 	uvc_status_put(stream->dev);
-
-	usb_autopm_put_interface(stream->dev->intf);
 	return 0;
 }
 

-- 
2.47.0.338.g60cca15819-goog