[media] v4l2 core: improve debug flag handling

The old debug field is renamed to dev_debug to ensure that existing drivers
(including out-of-tree drivers) that try to use the old name will no longer
compile. A comment has also been added that makes it explicit that drivers
shouldn't use this field.

Additional bits have been added to the debug flag to be more fine-grained
when debugging, especially when dealing with streaming ioctls and read,
write and poll. You want to enable those explicitly to prevent flooding
the log when streaming unless you actually want to do that.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

2 files changed, 22 insertions, 16 deletions

diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index a13cc6123dd2..86bb93fd7db8 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -47,15 +47,15 @@ static ssize_t index_show(struct device *cd,
 }
 static DEVICE_ATTR_RO(index);
 
-static ssize_t debug_show(struct device *cd,
+static ssize_t dev_debug_show(struct device *cd,
 			  struct device_attribute *attr, char *buf)
 {
 	struct video_device *vdev = to_video_device(cd);
 
-	return sprintf(buf, "%i\n", vdev->debug);
+	return sprintf(buf, "%i\n", vdev->dev_debug);
 }
 
-static ssize_t debug_store(struct device *cd, struct device_attribute *attr,
+static ssize_t dev_debug_store(struct device *cd, struct device_attribute *attr,
 			  const char *buf, size_t len)
 {
 	struct video_device *vdev = to_video_device(cd);
@@ -66,10 +66,10 @@ static ssize_t debug_store(struct device *cd, struct device_attribute *attr,
 	if (res)
 		return res;
 
-	vdev->debug = value;
+	vdev->dev_debug = value;
 	return len;
 }
-static DEVICE_ATTR_RW(debug);
+static DEVICE_ATTR_RW(dev_debug);
 
 static ssize_t name_show(struct device *cd,
 			 struct device_attribute *attr, char *buf)
@@ -82,7 +82,7 @@ static DEVICE_ATTR_RO(name);
 
 static struct attribute *video_device_attrs[] = {
 	&dev_attr_name.attr,
-	&dev_attr_debug.attr,
+	&dev_attr_dev_debug.attr,
 	&dev_attr_index.attr,
 	NULL,
 };
@@ -304,7 +304,8 @@ static ssize_t v4l2_read(struct file *filp, char __user *buf,
 		return -EINVAL;
 	if (video_is_registered(vdev))
 		ret = vdev->fops->read(filp, buf, sz, off);
-	if (vdev->debug)
+	if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
+	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
 		printk(KERN_DEBUG "%s: read: %zd (%d)\n",
 			video_device_node_name(vdev), sz, ret);
 	return ret;
@@ -320,7 +321,8 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf,
 		return -EINVAL;
 	if (video_is_registered(vdev))
 		ret = vdev->fops->write(filp, buf, sz, off);
-	if (vdev->debug)
+	if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
+	    (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
 		printk(KERN_DEBUG "%s: write: %zd (%d)\n",
 			video_device_node_name(vdev), sz, ret);
 	return ret;
@@ -335,7 +337,7 @@ static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
 		return DEFAULT_POLLMASK;
 	if (video_is_registered(vdev))
 		res = vdev->fops->poll(filp, poll);
-	if (vdev->debug > 2)
+	if (vdev->dev_debug & V4L2_DEV_DEBUG_POLL)
 		printk(KERN_DEBUG "%s: poll: %08x\n",
 			video_device_node_name(vdev), res);
 	return res;
@@ -404,7 +406,7 @@ static unsigned long v4l2_get_unmapped_area(struct file *filp,
 	if (!video_is_registered(vdev))
 		return -ENODEV;
 	ret = vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
-	if (vdev->debug)
+	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
 		printk(KERN_DEBUG "%s: get_unmapped_area (%d)\n",
 			video_device_node_name(vdev), ret);
 	return ret;
@@ -420,7 +422,7 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 		return -ENODEV;
 	if (video_is_registered(vdev))
 		ret = vdev->fops->mmap(filp, vm);
-	if (vdev->debug)
+	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
 		printk(KERN_DEBUG "%s: mmap (%d)\n",
 			video_device_node_name(vdev), ret);
 	return ret;
@@ -450,7 +452,7 @@ static int v4l2_open(struct inode *inode, struct file *filp)
 			ret = -ENODEV;
 	}
 
-	if (vdev->debug)
+	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
 		printk(KERN_DEBUG "%s: open (%d)\n",
 			video_device_node_name(vdev), ret);
 	/* decrease the refcount in case of an error */
@@ -467,7 +469,7 @@ static int v4l2_release(struct inode *inode, struct file *filp)
 
 	if (vdev->fops->release)
 		ret = vdev->fops->release(filp);
-	if (vdev->debug)
+	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
 		printk(KERN_DEBUG "%s: release\n",
 			video_device_node_name(vdev));
 
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index faac2f4e0f3a..b08407225db1 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2339,7 +2339,7 @@ static long __video_do_ioctl(struct file *file,
 	const struct v4l2_ioctl_info *info;
 	void *fh = file->private_data;
 	struct v4l2_fh *vfh = NULL;
-	int debug = vfd->debug;
+	int dev_debug = vfd->dev_debug;
 	long ret = -ENOTTY;
 
 	if (ops == NULL) {
@@ -2388,11 +2388,15 @@ static long __video_do_ioctl(struct file *file,
 	}
 
 done:
-	if (debug) {
+	if (dev_debug & (V4L2_DEV_DEBUG_IOCTL | V4L2_DEV_DEBUG_IOCTL_ARG)) {
+		if (!(dev_debug & V4L2_DEV_DEBUG_STREAMING) &&
+		    (cmd == VIDIOC_QBUF || cmd == VIDIOC_DQBUF))
+			return ret;
+
 		v4l_printk_ioctl(video_device_node_name(vfd), cmd);
 		if (ret < 0)
 			pr_cont(": error %ld", ret);
-		if (debug == V4L2_DEBUG_IOCTL)
+		if (!(dev_debug & V4L2_DEV_DEBUG_IOCTL_ARG))
 			pr_cont("\n");
 		else if (_IOC_DIR(cmd) == _IOC_NONE)
 			info->debug(arg, write_only);