V4L:some v4l drivers have error for video_register_device

For video_register_device(), it return zero means register success.It would be return zero or a negative number (on failure),it would not return a positive number.so it have better to use this to check err:

	int err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
	if (err != 0) {
		/*err code*/
	}

Signed-off-by Figo.zhang <[email protected]>

---

 Documentation/video4linux/v4l2-framework.txt |    2 +-
 drivers/media/radio/radio-maestro.c          |    2 +-
 drivers/media/radio/radio-si470x.c           |    2 +-
 drivers/media/video/cafe_ccic.c              |    2 +-
 drivers/media/video/cx231xx/cx231xx-video.c  |    2 +-
 drivers/media/video/em28xx/em28xx-video.c    |    2 +-
 drivers/media/video/et61x251/et61x251_core.c |    2 +-
 drivers/media/video/hdpvr/hdpvr-video.c      |    2 +-
 drivers/media/video/ivtv/ivtv-streams.c      |    2 +-
 drivers/media/video/sn9c102/sn9c102_core.c   |    2 +-
 drivers/media/video/stk-webcam.c             |    2 +-
 drivers/media/video/w9968cf.c                |    2 +-
 drivers/media/video/zc0301/zc0301_core.c     |    2 +-
 drivers/media/video/zr364xx.c                |    2 +-
 sound/i2c/other/tea575x-tuner.c              |    2 +-
 15 files changed, 15 insertions(+), 15 deletions(-)

Documentation/video4linux/v4l2-framework.txt +1 -1

index 854808b..250232a 100644
@@ -447,7 +447,7 @@ Next you register the video device: this will create the character device
 for you.
 
 	err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
-	if (err) {
+	if (err != 0) {
 		video_device_release(vdev); /* or kfree(my_vdev); */
 		return err;
 	}

drivers/media/radio/radio-maestro.c +1 -1

index 64d737c..b5e93c2 100644
@@ -379,7 +379,7 @@ static int __devinit maestro_probe(struct pci_dev *pdev,
 	video_set_drvdata(&dev->vdev, dev);
 
 	retval = video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr);
-	if (retval) {
+	if (retval != 0) {
 		v4l2_err(v4l2_dev, "can't register video device!\n");
 		goto errfr1;
 	}

drivers/media/radio/radio-si470x.c +1 -1

index bd945d0..edb520a 100644
@@ -1740,7 +1740,7 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
 
 	/* register video device */
 	retval = video_register_device(radio->videodev, VFL_TYPE_RADIO, radio_nr);
-	if (retval) {
+	if (retval != 0) {
 		printk(KERN_WARNING DRIVER_NAME
 				": Could not register video device\n");
 		goto err_all;

drivers/media/video/cafe_ccic.c +1 -1

index c4d181d..fd93698 100644
@@ -1974,7 +1974,7 @@ static int cafe_pci_probe(struct pci_dev *pdev,
 /*	cam->vdev.debug = V4L2_DEBUG_IOCTL_ARG;*/
 	cam->vdev.v4l2_dev = &cam->v4l2_dev;
 	ret = video_register_device(&cam->vdev, VFL_TYPE_GRABBER, -1);
-	if (ret)
+	if (ret != 0)
 		goto out_smbus;
 	video_set_drvdata(&cam->vdev, cam);
 

drivers/media/video/cx231xx/cx231xx-video.c +1 -1

index a23ae73..14e5008 100644
@@ -2382,7 +2382,7 @@ int cx231xx_register_analog_devices(struct cx231xx *dev)
 	/* register v4l2 video video_device */
 	ret = video_register_device(dev->vdev, VFL_TYPE_GRABBER,
 				    video_nr[dev->devno]);
-	if (ret) {
+	if (ret != 0) {
 		cx231xx_errdev("unable to register video device (error=%i).\n",
 			       ret);
 		return ret;

drivers/media/video/em28xx/em28xx-video.c +1 -1

index 882796e..dcc3aca 100644
@@ -2013,7 +2013,7 @@ int em28xx_register_analog_devices(struct em28xx *dev)
 	/* register v4l2 video video_device */
 	ret = video_register_device(dev->vdev, VFL_TYPE_GRABBER,
 				       video_nr[dev->devno]);
-	if (ret) {
+	if (ret != 0) {
 		em28xx_errdev("unable to register video device (error=%i).\n",
 			      ret);
 		return ret;

drivers/media/video/et61x251/et61x251_core.c +1 -1

index d1c1e45..8a767e1 100644
@@ -2591,7 +2591,7 @@ et61x251_usb_probe(struct usb_interface* intf, const struct usb_device_id* id)
 
 	err = video_register_device(cam->v4ldev, VFL_TYPE_GRABBER,
 				    video_nr[dev_nr]);
-	if (err) {
+	if (err != 0) {
 		DBG(1, "V4L2 device registration failed");
 		if (err == -ENFILE && video_nr[dev_nr] == -1)
 			DBG(1, "Free /dev/videoX node not found");

drivers/media/video/hdpvr/hdpvr-video.c +1 -1

index 3e6ffee..14c8488 100644
@@ -1237,7 +1237,7 @@ int hdpvr_register_videodev(struct hdpvr_device *dev, struct device *parent,
 	dev->video_dev->parent = parent;
 	video_set_drvdata(dev->video_dev, dev);
 
-	if (video_register_device(dev->video_dev, VFL_TYPE_GRABBER, devnum)) {
+	if (video_register_device(dev->video_dev, VFL_TYPE_GRABBER, devnum) != 0) {
 		v4l2_err(&dev->v4l2_dev, "video_device registration failed\n");
 		goto error;
 	}

drivers/media/video/ivtv/ivtv-streams.c +1 -1

index 15da017..1aca6b3 100644
@@ -261,7 +261,7 @@ static int ivtv_reg_dev(struct ivtv *itv, int type)
 	video_set_drvdata(s->vdev, s);
 
 	/* Register device. First try the desired minor, then any free one. */
-	if (video_register_device(s->vdev, vfl_type, num)) {
+	if (video_register_device(s->vdev, vfl_type, num) != 0) {
 		IVTV_ERR("Couldn't register v4l2 device for %s kernel number %d\n",
 				s->name, num);
 		video_device_release(s->vdev);

drivers/media/video/sn9c102/sn9c102_core.c +1 -1

index 23edfdc..55242c4 100644
@@ -3334,7 +3334,7 @@ sn9c102_usb_probe(struct usb_interface* intf, const struct usb_device_id* id)
 
 	err = video_register_device(cam->v4ldev, VFL_TYPE_GRABBER,
 				    video_nr[dev_nr]);
-	if (err) {
+	if (err != 0) {
 		DBG(1, "V4L2 device registration failed");
 		if (err == -ENFILE && video_nr[dev_nr] == -1)
 			DBG(1, "Free /dev/videoX node not found");

drivers/media/video/stk-webcam.c +1 -1

index 1a6d39c..1a7aca0 100644
@@ -1323,7 +1323,7 @@ static int stk_register_video_device(struct stk_camera *dev)
 	dev->vdev.debug = debug;
 	dev->vdev.parent = &dev->interface->dev;
 	err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
-	if (err)
+	if (err != 0)
 		STK_ERROR("v4l registration failed\n");
 	else
 		STK_INFO("Syntek USB2.0 Camera is now controlling video device"

drivers/media/video/w9968cf.c +1 -1

index f59b2bd..5f56e90 100644
@@ -3500,7 +3500,7 @@ w9968cf_usb_probe(struct usb_interface* intf, const struct usb_device_id* id)
 
 	err = video_register_device(cam->v4ldev, VFL_TYPE_GRABBER,
 				    video_nr[dev_nr]);
-	if (err) {
+	if (err != 0) {
 		DBG(1, "V4L device registration failed")
 		if (err == -ENFILE && video_nr[dev_nr] == -1)
 			DBG(2, "Couldn't find a free /dev/videoX node")

drivers/media/video/zc0301/zc0301_core.c +1 -1

index 9697104..05296fc 100644
@@ -1991,7 +1991,7 @@ zc0301_usb_probe(struct usb_interface* intf, const struct usb_device_id* id)
 
 	err = video_register_device(cam->v4ldev, VFL_TYPE_GRABBER,
 				    video_nr[dev_nr]);
-	if (err) {
+	if (err != 0) {
 		DBG(1, "V4L2 device registration failed");
 		if (err == -ENFILE && video_nr[dev_nr] == -1)
 			DBG(1, "Free /dev/videoX node not found");

drivers/media/video/zr364xx.c +1 -1

index ac169c9..83d0aea 100644
@@ -857,7 +857,7 @@ static int zr364xx_probe(struct usb_interface *intf,
 	mutex_init(&cam->lock);
 
 	err = video_register_device(cam->vdev, VFL_TYPE_GRABBER, -1);
-	if (err) {
+	if (err != 0) {
 		dev_err(&udev->dev, "video_register_device failed\n");
 		video_device_release(cam->vdev);
 		kfree(cam->buffer);

sound/i2c/other/tea575x-tuner.c +1 -1

index d31c373..27bc7be 100644
@@ -324,7 +324,7 @@ void snd_tea575x_init(struct snd_tea575x *tea)
 
 	retval = video_register_device(tea575x_radio_inst,
 				       VFL_TYPE_RADIO, radio_nr);
-	if (retval) {
+	if (retval != 0) {
 		printk(KERN_ERR "tea575x-tuner: can't register video device!\n");
 		kfree(tea575x_radio_inst);
 		return;

The function video_register_device() will call the video_register_device_index(). In this function, firtly it will do some argments check , if failed,it will return a negative number such as -EINVAL, and then do cdev_alloc() and device_register(), if success return zero. so video_register_device_index() canot return a a positive number.

for example, see the drivers/media/video/stk-webcam.c (line 1325):

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

in my opinion, it will be cleaner to do something like this:

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err != 0)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

Hi,

Quoted 15 lines · On Thursday 04 June 2009 06:20:07 figo.zhang wrote:

The function video_register_device() will call the video_register_device_index(). In this function, firtly it will do some argments check , if failed,it will return a negative number such as -EINVAL, and then do cdev_alloc() and device_register(), if success return zero. so video_register_device_index() canot return a a positive number.

for example, see the drivers/media/video/stk-webcam.c (line 1325):

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

Quoted 8 lines

in my opinion, it will be cleaner to do something like this:

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err != 0)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

What's the difference ? (err != 0) and (err) are identical.

Best regards,

Laurent Pinchart

Quoted 27 lines

Hi,

Quoted 23 lines · On Thursday 04 June 2009 06:20:07 figo.zhang wrote:

The function video_register_device() will call the video_register_device_index(). In this function, firtly it will do some argments check , if failed,it will return a negative number such as -EINVAL, and then do cdev_alloc() and device_register(), if success return zero. so video_register_device_index() canot return a a positive number.

for example, see the drivers/media/video/stk-webcam.c (line 1325):

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

in my opinion, it will be cleaner to do something like this:

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err != 0)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

Quoted 5 lines

What's the difference ? (err != 0) and (err) are identical.

Best regards,

Laurent Pinchart

yes, it is the same, but it is easy for reading.

Hi,

Quoted 15 lines · On Thursday 04 June 2009 06:20:07 figo.zhang wrote:

The function video_register_device() will call the video_register_device_index(). In this function, firtly it will do some argments check , if failed,it will return a negative number such as -EINVAL, and then do cdev_alloc() and device_register(), if success return zero. so video_register_device_index() canot return a a positive number.

for example, see the drivers/media/video/stk-webcam.c (line 1325):

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

Quoted 8 lines

in my opinion, it will be cleaner to do something like this:

err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
	if (err != 0)
		STK_ERROR("v4l registration failed\n");
	else
		STK_INFO("Syntek USB2.0 Camera is now controlling video device"
			" /dev/video%d\n", dev->vdev.num);

What's the difference ? (err != 0) and (err) are identical.

Best regards,

Laurent Pinchart