---

yaml
---
r: 306292
b: refs/heads/master
c: 8ab75e3
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ccfc97bdb5ae8b8edc55169ac6924e08449836ac
+refs/heads/master: 8ab75e3ecd8f232d9564510f0c601a6aa7a149ea

trunk/Documentation/video4linux/v4l2-framework.txt

@@ -580,19 +580,25 @@ allocated memory.
 You should also set these fields:
 
 - v4l2_dev: set to the v4l2_device parent device.
+
 - name: set to something descriptive and unique.
+
 - fops: set to the v4l2_file_operations struct.
+
 - ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance
   (highly recommended to use this and it might become compulsory in the
   future!), then set this to your v4l2_ioctl_ops struct.
+
 - lock: leave to NULL if you want to do all the locking in the driver.
   Otherwise you give it a pointer to a struct mutex_lock and before any
   of the v4l2_file_operations is called this lock will be taken by the
-  core and released afterwards.
+  core and released afterwards. See the next section for more details.
+
 - prio: keeps track of the priorities. Used to implement VIDIOC_G/S_PRIORITY.
   If left to NULL, then it will use the struct v4l2_prio_state in v4l2_device.
   If you want to have a separate priority state per (group of) device node(s),
   then you can point it to your own struct v4l2_prio_state.
+
 - parent: you only set this if v4l2_device was registered with NULL as
   the parent device struct. This only happens in cases where one hardware
   device has multiple PCI devices that all share the same v4l2_device core.
@@ -602,6 +608,7 @@ You should also set these fields:
   (cx8802). Since the v4l2_device cannot be associated with a particular
   PCI device it is setup without a parent device. But when the struct
   video_device is setup you do know which parent PCI device to use.
+
 - flags: optional. Set to V4L2_FL_USE_FH_PRIO if you want to let the framework
   handle the VIDIOC_G/S_PRIORITY ioctls. This requires that you use struct
   v4l2_fh. Eventually this flag will disappear once all drivers use the core
@@ -634,8 +641,22 @@ v4l2_file_operations and locking
 --------------------------------
 
 You can set a pointer to a mutex_lock in struct video_device. Usually this
-will be either a top-level mutex or a mutex per device node. If you want
-finer-grained locking then you have to set it to NULL and do you own locking.
+will be either a top-level mutex or a mutex per device node. By default this
+lock will be used for each file operation and ioctl, but you can disable
+locking for selected ioctls by calling:
+
+	void v4l2_dont_use_lock(struct video_device *vdev, unsigned int cmd);
+
+E.g.: v4l2_dont_use_lock(vdev, VIDIOC_DQBUF);
+
+You have to call this before you register the video_device.
+
+Particularly with USB drivers where certain commands such as setting controls
+can take a long time you may want to do your own locking for the buffer queuing
+ioctls.
+
+If you want still finer-grained locking then you have to set mutex_lock to NULL
+and do you own locking completely.
 
 It is up to the driver developer to decide which method to use. However, if
 your driver has high-latency operations (for example, changing the exposure

trunk/drivers/media/video/v4l2-dev.c

@@ -322,11 +322,19 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	int ret = -ENODEV;
 
 	if (vdev->fops->unlocked_ioctl) {
-		if (vdev->lock && mutex_lock_interruptible(vdev->lock))
-			return -ERESTARTSYS;
+		bool locked = false;
+
+		if (vdev->lock) {
+			/* always lock unless the cmd is marked as "don't use lock" */
+			locked = !v4l2_is_known_ioctl(cmd) ||
+				 !test_bit(_IOC_NR(cmd), vdev->dont_use_lock);
+
+			if (locked && mutex_lock_interruptible(vdev->lock))
+				return -ERESTARTSYS;
+		}
 		if (video_is_registered(vdev))
 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
-		if (vdev->lock)
+		if (locked)
 			mutex_unlock(vdev->lock);
 	} else if (vdev->fops->ioctl) {
 		/* This code path is a replacement for the BKL. It is a major

trunk/drivers/media/video/v4l2-ioctl.c

@@ -195,93 +195,106 @@ static const char *v4l2_memory_names[] = {
 
 /* ------------------------------------------------------------------ */
 /* debug help functions                                               */
-static const char *v4l2_ioctls[] = {
-	[_IOC_NR(VIDIOC_QUERYCAP)]         = "VIDIOC_QUERYCAP",
-	[_IOC_NR(VIDIOC_RESERVED)]         = "VIDIOC_RESERVED",
-	[_IOC_NR(VIDIOC_ENUM_FMT)]         = "VIDIOC_ENUM_FMT",
-	[_IOC_NR(VIDIOC_G_FMT)]            = "VIDIOC_G_FMT",
-	[_IOC_NR(VIDIOC_S_FMT)]            = "VIDIOC_S_FMT",
-	[_IOC_NR(VIDIOC_REQBUFS)]          = "VIDIOC_REQBUFS",
-	[_IOC_NR(VIDIOC_QUERYBUF)]         = "VIDIOC_QUERYBUF",
-	[_IOC_NR(VIDIOC_G_FBUF)]           = "VIDIOC_G_FBUF",
-	[_IOC_NR(VIDIOC_S_FBUF)]           = "VIDIOC_S_FBUF",
-	[_IOC_NR(VIDIOC_OVERLAY)]          = "VIDIOC_OVERLAY",
-	[_IOC_NR(VIDIOC_QBUF)]             = "VIDIOC_QBUF",
-	[_IOC_NR(VIDIOC_DQBUF)]            = "VIDIOC_DQBUF",
-	[_IOC_NR(VIDIOC_STREAMON)]         = "VIDIOC_STREAMON",
-	[_IOC_NR(VIDIOC_STREAMOFF)]        = "VIDIOC_STREAMOFF",
-	[_IOC_NR(VIDIOC_G_PARM)]           = "VIDIOC_G_PARM",
-	[_IOC_NR(VIDIOC_S_PARM)]           = "VIDIOC_S_PARM",
-	[_IOC_NR(VIDIOC_G_STD)]            = "VIDIOC_G_STD",
-	[_IOC_NR(VIDIOC_S_STD)]            = "VIDIOC_S_STD",
-	[_IOC_NR(VIDIOC_ENUMSTD)]          = "VIDIOC_ENUMSTD",
-	[_IOC_NR(VIDIOC_ENUMINPUT)]        = "VIDIOC_ENUMINPUT",
-	[_IOC_NR(VIDIOC_G_CTRL)]           = "VIDIOC_G_CTRL",
-	[_IOC_NR(VIDIOC_S_CTRL)]           = "VIDIOC_S_CTRL",
-	[_IOC_NR(VIDIOC_G_TUNER)]          = "VIDIOC_G_TUNER",
-	[_IOC_NR(VIDIOC_S_TUNER)]          = "VIDIOC_S_TUNER",
-	[_IOC_NR(VIDIOC_G_AUDIO)]          = "VIDIOC_G_AUDIO",
-	[_IOC_NR(VIDIOC_S_AUDIO)]          = "VIDIOC_S_AUDIO",
-	[_IOC_NR(VIDIOC_QUERYCTRL)]        = "VIDIOC_QUERYCTRL",
-	[_IOC_NR(VIDIOC_QUERYMENU)]        = "VIDIOC_QUERYMENU",
-	[_IOC_NR(VIDIOC_G_INPUT)]          = "VIDIOC_G_INPUT",
-	[_IOC_NR(VIDIOC_S_INPUT)]          = "VIDIOC_S_INPUT",
-	[_IOC_NR(VIDIOC_G_OUTPUT)]         = "VIDIOC_G_OUTPUT",
-	[_IOC_NR(VIDIOC_S_OUTPUT)]         = "VIDIOC_S_OUTPUT",
-	[_IOC_NR(VIDIOC_ENUMOUTPUT)]       = "VIDIOC_ENUMOUTPUT",
-	[_IOC_NR(VIDIOC_G_AUDOUT)]         = "VIDIOC_G_AUDOUT",
-	[_IOC_NR(VIDIOC_S_AUDOUT)]         = "VIDIOC_S_AUDOUT",
-	[_IOC_NR(VIDIOC_G_MODULATOR)]      = "VIDIOC_G_MODULATOR",
-	[_IOC_NR(VIDIOC_S_MODULATOR)]      = "VIDIOC_S_MODULATOR",
-	[_IOC_NR(VIDIOC_G_FREQUENCY)]      = "VIDIOC_G_FREQUENCY",
-	[_IOC_NR(VIDIOC_S_FREQUENCY)]      = "VIDIOC_S_FREQUENCY",
-	[_IOC_NR(VIDIOC_CROPCAP)]          = "VIDIOC_CROPCAP",
-	[_IOC_NR(VIDIOC_G_CROP)]           = "VIDIOC_G_CROP",
-	[_IOC_NR(VIDIOC_S_CROP)]           = "VIDIOC_S_CROP",
-	[_IOC_NR(VIDIOC_G_SELECTION)]      = "VIDIOC_G_SELECTION",
-	[_IOC_NR(VIDIOC_S_SELECTION)]      = "VIDIOC_S_SELECTION",
-	[_IOC_NR(VIDIOC_G_JPEGCOMP)]       = "VIDIOC_G_JPEGCOMP",
-	[_IOC_NR(VIDIOC_S_JPEGCOMP)]       = "VIDIOC_S_JPEGCOMP",
-	[_IOC_NR(VIDIOC_QUERYSTD)]         = "VIDIOC_QUERYSTD",
-	[_IOC_NR(VIDIOC_TRY_FMT)]          = "VIDIOC_TRY_FMT",
-	[_IOC_NR(VIDIOC_ENUMAUDIO)]        = "VIDIOC_ENUMAUDIO",
-	[_IOC_NR(VIDIOC_ENUMAUDOUT)]       = "VIDIOC_ENUMAUDOUT",
-	[_IOC_NR(VIDIOC_G_PRIORITY)]       = "VIDIOC_G_PRIORITY",
-	[_IOC_NR(VIDIOC_S_PRIORITY)]       = "VIDIOC_S_PRIORITY",
-	[_IOC_NR(VIDIOC_G_SLICED_VBI_CAP)] = "VIDIOC_G_SLICED_VBI_CAP",
-	[_IOC_NR(VIDIOC_LOG_STATUS)]       = "VIDIOC_LOG_STATUS",
-	[_IOC_NR(VIDIOC_G_EXT_CTRLS)]      = "VIDIOC_G_EXT_CTRLS",
-	[_IOC_NR(VIDIOC_S_EXT_CTRLS)]      = "VIDIOC_S_EXT_CTRLS",
-	[_IOC_NR(VIDIOC_TRY_EXT_CTRLS)]    = "VIDIOC_TRY_EXT_CTRLS",
-#if 1
-	[_IOC_NR(VIDIOC_ENUM_FRAMESIZES)]  = "VIDIOC_ENUM_FRAMESIZES",
-	[_IOC_NR(VIDIOC_ENUM_FRAMEINTERVALS)] = "VIDIOC_ENUM_FRAMEINTERVALS",
-	[_IOC_NR(VIDIOC_G_ENC_INDEX)] 	   = "VIDIOC_G_ENC_INDEX",
-	[_IOC_NR(VIDIOC_ENCODER_CMD)] 	   = "VIDIOC_ENCODER_CMD",
-	[_IOC_NR(VIDIOC_TRY_ENCODER_CMD)]  = "VIDIOC_TRY_ENCODER_CMD",
-
-	[_IOC_NR(VIDIOC_DECODER_CMD)]	   = "VIDIOC_DECODER_CMD",
-	[_IOC_NR(VIDIOC_TRY_DECODER_CMD)]  = "VIDIOC_TRY_DECODER_CMD",
-	[_IOC_NR(VIDIOC_DBG_S_REGISTER)]   = "VIDIOC_DBG_S_REGISTER",
-	[_IOC_NR(VIDIOC_DBG_G_REGISTER)]   = "VIDIOC_DBG_G_REGISTER",
-
-	[_IOC_NR(VIDIOC_DBG_G_CHIP_IDENT)] = "VIDIOC_DBG_G_CHIP_IDENT",
-	[_IOC_NR(VIDIOC_S_HW_FREQ_SEEK)]   = "VIDIOC_S_HW_FREQ_SEEK",
-#endif
-	[_IOC_NR(VIDIOC_ENUM_DV_PRESETS)]  = "VIDIOC_ENUM_DV_PRESETS",
-	[_IOC_NR(VIDIOC_S_DV_PRESET)]	   = "VIDIOC_S_DV_PRESET",
-	[_IOC_NR(VIDIOC_G_DV_PRESET)]	   = "VIDIOC_G_DV_PRESET",
-	[_IOC_NR(VIDIOC_QUERY_DV_PRESET)]  = "VIDIOC_QUERY_DV_PRESET",
-	[_IOC_NR(VIDIOC_S_DV_TIMINGS)]     = "VIDIOC_S_DV_TIMINGS",
-	[_IOC_NR(VIDIOC_G_DV_TIMINGS)]     = "VIDIOC_G_DV_TIMINGS",
-	[_IOC_NR(VIDIOC_DQEVENT)]	   = "VIDIOC_DQEVENT",
-	[_IOC_NR(VIDIOC_SUBSCRIBE_EVENT)]  = "VIDIOC_SUBSCRIBE_EVENT",
-	[_IOC_NR(VIDIOC_UNSUBSCRIBE_EVENT)] = "VIDIOC_UNSUBSCRIBE_EVENT",
-	[_IOC_NR(VIDIOC_CREATE_BUFS)]      = "VIDIOC_CREATE_BUFS",
-	[_IOC_NR(VIDIOC_PREPARE_BUF)]      = "VIDIOC_PREPARE_BUF",
+
+struct v4l2_ioctl_info {
+	unsigned int ioctl;
+	const char * const name;
+};
+
+#define IOCTL_INFO(_ioctl) [_IOC_NR(_ioctl)] = {	\
+	.ioctl = _ioctl,				\
+	.name = #_ioctl,				\
+}
+
+static struct v4l2_ioctl_info v4l2_ioctls[] = {
+	IOCTL_INFO(VIDIOC_QUERYCAP),
+	IOCTL_INFO(VIDIOC_ENUM_FMT),
+	IOCTL_INFO(VIDIOC_G_FMT),
+	IOCTL_INFO(VIDIOC_S_FMT),
+	IOCTL_INFO(VIDIOC_REQBUFS),
+	IOCTL_INFO(VIDIOC_QUERYBUF),
+	IOCTL_INFO(VIDIOC_G_FBUF),
+	IOCTL_INFO(VIDIOC_S_FBUF),
+	IOCTL_INFO(VIDIOC_OVERLAY),
+	IOCTL_INFO(VIDIOC_QBUF),
+	IOCTL_INFO(VIDIOC_DQBUF),
+	IOCTL_INFO(VIDIOC_STREAMON),
+	IOCTL_INFO(VIDIOC_STREAMOFF),
+	IOCTL_INFO(VIDIOC_G_PARM),
+	IOCTL_INFO(VIDIOC_S_PARM),
+	IOCTL_INFO(VIDIOC_G_STD),
+	IOCTL_INFO(VIDIOC_S_STD),
+	IOCTL_INFO(VIDIOC_ENUMSTD),
+	IOCTL_INFO(VIDIOC_ENUMINPUT),
+	IOCTL_INFO(VIDIOC_G_CTRL),
+	IOCTL_INFO(VIDIOC_S_CTRL),
+	IOCTL_INFO(VIDIOC_G_TUNER),
+	IOCTL_INFO(VIDIOC_S_TUNER),
+	IOCTL_INFO(VIDIOC_G_AUDIO),
+	IOCTL_INFO(VIDIOC_S_AUDIO),
+	IOCTL_INFO(VIDIOC_QUERYCTRL),
+	IOCTL_INFO(VIDIOC_QUERYMENU),
+	IOCTL_INFO(VIDIOC_G_INPUT),
+	IOCTL_INFO(VIDIOC_S_INPUT),
+	IOCTL_INFO(VIDIOC_G_OUTPUT),
+	IOCTL_INFO(VIDIOC_S_OUTPUT),
+	IOCTL_INFO(VIDIOC_ENUMOUTPUT),
+	IOCTL_INFO(VIDIOC_G_AUDOUT),
+	IOCTL_INFO(VIDIOC_S_AUDOUT),
+	IOCTL_INFO(VIDIOC_G_MODULATOR),
+	IOCTL_INFO(VIDIOC_S_MODULATOR),
+	IOCTL_INFO(VIDIOC_G_FREQUENCY),
+	IOCTL_INFO(VIDIOC_S_FREQUENCY),
+	IOCTL_INFO(VIDIOC_CROPCAP),
+	IOCTL_INFO(VIDIOC_G_CROP),
+	IOCTL_INFO(VIDIOC_S_CROP),
+	IOCTL_INFO(VIDIOC_G_SELECTION),
+	IOCTL_INFO(VIDIOC_S_SELECTION),
+	IOCTL_INFO(VIDIOC_G_JPEGCOMP),
+	IOCTL_INFO(VIDIOC_S_JPEGCOMP),
+	IOCTL_INFO(VIDIOC_QUERYSTD),
+	IOCTL_INFO(VIDIOC_TRY_FMT),
+	IOCTL_INFO(VIDIOC_ENUMAUDIO),
+	IOCTL_INFO(VIDIOC_ENUMAUDOUT),
+	IOCTL_INFO(VIDIOC_G_PRIORITY),
+	IOCTL_INFO(VIDIOC_S_PRIORITY),
+	IOCTL_INFO(VIDIOC_G_SLICED_VBI_CAP),
+	IOCTL_INFO(VIDIOC_LOG_STATUS),
+	IOCTL_INFO(VIDIOC_G_EXT_CTRLS),
+	IOCTL_INFO(VIDIOC_S_EXT_CTRLS),
+	IOCTL_INFO(VIDIOC_TRY_EXT_CTRLS),
+	IOCTL_INFO(VIDIOC_ENUM_FRAMESIZES),
+	IOCTL_INFO(VIDIOC_ENUM_FRAMEINTERVALS),
+	IOCTL_INFO(VIDIOC_G_ENC_INDEX),
+	IOCTL_INFO(VIDIOC_ENCODER_CMD),
+	IOCTL_INFO(VIDIOC_TRY_ENCODER_CMD),
+	IOCTL_INFO(VIDIOC_DECODER_CMD),
+	IOCTL_INFO(VIDIOC_TRY_DECODER_CMD),
+	IOCTL_INFO(VIDIOC_DBG_S_REGISTER),
+	IOCTL_INFO(VIDIOC_DBG_G_REGISTER),
+	IOCTL_INFO(VIDIOC_DBG_G_CHIP_IDENT),
+	IOCTL_INFO(VIDIOC_S_HW_FREQ_SEEK),
+	IOCTL_INFO(VIDIOC_ENUM_DV_PRESETS),
+	IOCTL_INFO(VIDIOC_S_DV_PRESET),
+	IOCTL_INFO(VIDIOC_G_DV_PRESET),
+	IOCTL_INFO(VIDIOC_QUERY_DV_PRESET),
+	IOCTL_INFO(VIDIOC_S_DV_TIMINGS),
+	IOCTL_INFO(VIDIOC_G_DV_TIMINGS),
+	IOCTL_INFO(VIDIOC_DQEVENT),
+	IOCTL_INFO(VIDIOC_SUBSCRIBE_EVENT),
+	IOCTL_INFO(VIDIOC_UNSUBSCRIBE_EVENT),
+	IOCTL_INFO(VIDIOC_CREATE_BUFS),
+	IOCTL_INFO(VIDIOC_PREPARE_BUF),
 };
 #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
 
+bool v4l2_is_known_ioctl(unsigned int cmd)
+{
+	if (_IOC_NR(cmd) >= V4L2_IOCTLS)
+		return false;
+	return v4l2_ioctls[_IOC_NR(cmd)].ioctl == cmd;
+}
+
 /* Common ioctl debug function. This function can be used by
    external ioctl messages as well as internal V4L ioctl */
 void v4l_printk_ioctl(unsigned int cmd)
@@ -297,7 +310,7 @@ void v4l_printk_ioctl(unsigned int cmd)
 			type = "v4l2";
 			break;
 		}
-		printk("%s", v4l2_ioctls[_IOC_NR(cmd)]);
+		printk("%s", v4l2_ioctls[_IOC_NR(cmd)].name);
 		return;
 	default:
 		type = "unknown";
@@ -1948,9 +1961,9 @@ static long __video_do_ioctl(struct file *file,
 				vfd->v4l2_dev->name);
 		break;
 	}
-#ifdef CONFIG_VIDEO_ADV_DEBUG
 	case VIDIOC_DBG_G_REGISTER:
 	{
+#ifdef CONFIG_VIDEO_ADV_DEBUG
 		struct v4l2_dbg_register *p = arg;
 
 		if (ops->vidioc_g_register) {
@@ -1959,10 +1972,12 @@ static long __video_do_ioctl(struct file *file,
 			else
 				ret = ops->vidioc_g_register(file, fh, p);
 		}
+#endif
 		break;
 	}
 	case VIDIOC_DBG_S_REGISTER:
 	{
+#ifdef CONFIG_VIDEO_ADV_DEBUG
 		struct v4l2_dbg_register *p = arg;
 
 		if (ops->vidioc_s_register) {
@@ -1971,9 +1986,9 @@ static long __video_do_ioctl(struct file *file,
 			else
 				ret = ops->vidioc_s_register(file, fh, p);
 		}
+#endif
 		break;
 	}
-#endif
 	case VIDIOC_DBG_G_CHIP_IDENT:
 	{
 		struct v4l2_dbg_chip_ident *p = arg;

trunk/include/media/v4l2-dev.h

@@ -128,6 +128,7 @@ struct video_device
 	const struct v4l2_ioctl_ops *ioctl_ops;
 
 	/* serialization lock */
+	DECLARE_BITMAP(dont_use_lock, BASE_VIDIOC_PRIVATE);
 	struct mutex *lock;
 };
 
@@ -173,6 +174,16 @@ void video_device_release(struct video_device *vdev);
    a dubious construction at best. */
 void video_device_release_empty(struct video_device *vdev);
 
+/* returns true if cmd is a known V4L2 ioctl */
+bool v4l2_is_known_ioctl(unsigned int cmd);
+
+/* mark that this command shouldn't use core locking */
+static inline void v4l2_dont_use_lock(struct video_device *vdev, unsigned int cmd)
+{
+	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
+		set_bit(_IOC_NR(cmd), vdev->dont_use_lock);
+}
+
 /* helper functions to access driver private data. */
 static inline void *video_get_drvdata(struct video_device *vdev)
 {