From 4a77a8361fe79b78b741640b484a97c8d47e307f Mon Sep 17 00:00:00 2001 From: Hans Verkuil <hans.verkuil@cisco.com> Date: Mon, 2 Jul 2012 05:43:34 -0300 Subject: [media] v4l2-framework.txt: Update the locking documentation This documents the new queue->lock and how to use it. It also removes the documentation of v4l2_disable_ioctl_locking: this is only used in gspca and will be removed once gspca has been converted to vb2. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- Documentation/video4linux/v4l2-framework.txt | 73 +++++++++++++++------------- 1 file changed, 39 insertions(+), 34 deletions(-) (limited to 'Documentation/video4linux') diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 1f59052..89318be 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -594,6 +594,15 @@ You should also set these fields: unlocked_ioctl file operation is called this lock will be taken by the core and released afterwards. See the next section for more details. +- queue: a pointer to the struct vb2_queue associated with this device node. + If queue is non-NULL, and queue->lock is non-NULL, then queue->lock is + used for the queuing ioctls (VIDIOC_REQBUFS, CREATE_BUFS, QBUF, DQBUF, + QUERYBUF, PREPARE_BUF, STREAMON and STREAMOFF) instead of the lock above. + That way the vb2 queuing framework does not have to wait for other ioctls. + This queue pointer is also used by the vb2 helper functions to check for + queuing ownership (i.e. is the filehandle calling it allowed to do the + operation). + - 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), @@ -647,47 +656,43 @@ manually set the struct media_entity type and name fields. A reference to the entity will be automatically acquired/released when the video device is opened/closed. -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. By default this -lock will be used for unlocked_ioctl, but you can disable locking for -selected ioctls by calling: - - void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd); - -E.g.: v4l2_disable_ioctl_locking(vdev, VIDIOC_DQBUF); +ioctls and locking +------------------ -You have to call this before you register the video_device. +The V4L core provides optional locking services. The main service is the +lock field in struct video_device, which is a pointer to a mutex. If you set +this pointer, then that will be used by unlocked_ioctl to serialize all ioctls. -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 are using the videobuf2 framework, then there is a second lock that you +can set: video_device->queue->lock. If set, then this lock will be used instead +of video_device->lock to serialize all queuing ioctls (see the previous section +for the full list of those ioctls). -If you want still finer-grained locking then you have to set mutex_lock to NULL -and do you own locking completely. +The advantage of using a different lock for the queuing ioctls is that for some +drivers (particularly USB drivers) certain commands such as setting controls +can take a long time, so you want to use a separate lock for the buffer queuing +ioctls. That way your VIDIOC_DQBUF doesn't stall because the driver is busy +changing the e.g. exposure of the webcam. -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 -of a USB webcam might take a long time), then you might be better off with -doing your own locking if you want to allow the user to do other things with -the device while waiting for the high-latency command to finish. +Of course, you can always do all the locking yourself by leaving both lock +pointers at NULL. -If a lock is specified then all ioctl commands will be serialized on that -lock. If you use videobuf then you must pass the same lock to the videobuf -queue initialize function: if videobuf has to wait for a frame to arrive, then -it will temporarily unlock the lock and relock it afterwards. If your driver -also waits in the code, then you should do the same to allow other processes -to access the device node while the first process is waiting for something. +If you use the old videobuf then you must pass the video_device lock to the +videobuf queue initialize function: if videobuf has to wait for a frame to +arrive, then it will temporarily unlock the lock and relock it afterwards. If +your driver also waits in the code, then you should do the same to allow other +processes to access the device node while the first process is waiting for +something. In the case of videobuf2 you will need to implement the wait_prepare and -wait_finish callbacks to unlock/lock if applicable. In particular, if you use -the lock in struct video_device then you must unlock/lock this mutex in -wait_prepare and wait_finish. - -The implementation of a hotplug disconnect should also take the lock before -calling v4l2_device_disconnect. +wait_finish callbacks to unlock/lock if applicable. If you use the queue->lock +pointer, then you can use the helper functions vb2_ops_wait_prepare/finish. + +The implementation of a hotplug disconnect should also take the lock from +video_device before calling v4l2_device_disconnect. If you are also using +video_device->queue->lock, then you have to first lock video_device->queue->lock +followed by video_device->lock. That way you can be sure no ioctl is running +when you call v4l2_device_disconnect. video_device registration ------------------------- -- cgit v1.1 From f9028317b2046ea13595c55fb29922d8d97cf497 Mon Sep 17 00:00:00 2001 From: Jesper Juhl <jj@chaosbits.net> Date: Fri, 20 Jul 2012 22:35:17 +0200 Subject: Documentation: Add newline at end-of-file to files lacking one This patch simply adds a newline character at end-of-file to those files in Documentation/ that currently lack one. This is done for a few different reasons: A) It's rather annoying when you do "cat some_file.txt" that your prompt/cursor ends up at the end of the last line of output rather than on a new line. B) Some tools that process files line-by-line may get confused by the lack of a newline on the last line. C) The "\ No newline at end of file" line in diffs annoys me for some reason. So, let's just add the missing newline once and for all. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz> --- Documentation/video4linux/cpia2_overview.txt | 2 +- Documentation/video4linux/stv680.txt | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/video4linux') diff --git a/Documentation/video4linux/cpia2_overview.txt b/Documentation/video4linux/cpia2_overview.txt index a6e5366..ad6adbe 100644 --- a/Documentation/video4linux/cpia2_overview.txt +++ b/Documentation/video4linux/cpia2_overview.txt @@ -35,4 +35,4 @@ the camera. There are three modes for this. Block mode requests a number of contiguous registers. Random mode reads or writes random registers with a tuple structure containing address/value pairs. The repeat mode is only used by VP4 to load a firmware patch. It contains a starting address and -a sequence of bytes to be written into a gpio port. \ No newline at end of file +a sequence of bytes to be written into a gpio port. diff --git a/Documentation/video4linux/stv680.txt b/Documentation/video4linux/stv680.txt index 4f8946f..e3de336 100644 --- a/Documentation/video4linux/stv680.txt +++ b/Documentation/video4linux/stv680.txt @@ -50,4 +50,4 @@ The latest info on this driver can be found at: http://personal.clt.bellsouth.net/~kjsisson or at http://stv0680-usb.sourceforge.net -Any questions to me can be send to: kjsisson@bellsouth.net \ No newline at end of file +Any questions to me can be send to: kjsisson@bellsouth.net -- cgit v1.1 From 79980d9c985aa58db50f388634739419e2e20a5a Mon Sep 17 00:00:00 2001 From: Jesper Juhl <jj@chaosbits.net> Date: Fri, 20 Jul 2012 16:35:17 -0300 Subject: [media] Documentation: Add newline at end-of-file to files lacking one This patch simply adds a newline character at end-of-file to those files in Documentation/ that currently lack one. This is done for a few different reasons: A) It's rather annoying when you do "cat some_file.txt" that your prompt/cursor ends up at the end of the last line of output rather than on a new line. B) Some tools that process files line-by-line may get confused by the lack of a newline on the last line. C) The "\ No newline at end of file" line in diffs annoys me for some reason. So, let's just add the missing newline once and for all. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- Documentation/video4linux/cpia2_overview.txt | 2 +- Documentation/video4linux/stv680.txt | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/video4linux') diff --git a/Documentation/video4linux/cpia2_overview.txt b/Documentation/video4linux/cpia2_overview.txt index a6e5366..ad6adbe 100644 --- a/Documentation/video4linux/cpia2_overview.txt +++ b/Documentation/video4linux/cpia2_overview.txt @@ -35,4 +35,4 @@ the camera. There are three modes for this. Block mode requests a number of contiguous registers. Random mode reads or writes random registers with a tuple structure containing address/value pairs. The repeat mode is only used by VP4 to load a firmware patch. It contains a starting address and -a sequence of bytes to be written into a gpio port. \ No newline at end of file +a sequence of bytes to be written into a gpio port. diff --git a/Documentation/video4linux/stv680.txt b/Documentation/video4linux/stv680.txt index 4f8946f..e3de336 100644 --- a/Documentation/video4linux/stv680.txt +++ b/Documentation/video4linux/stv680.txt @@ -50,4 +50,4 @@ The latest info on this driver can be found at: http://personal.clt.bellsouth.net/~kjsisson or at http://stv0680-usb.sourceforge.net -Any questions to me can be send to: kjsisson@bellsouth.net \ No newline at end of file +Any questions to me can be send to: kjsisson@bellsouth.net -- cgit v1.1 From 9d2952d70f175193b609929427a88a62eaa381bb Mon Sep 17 00:00:00 2001 From: Tony Gentile <tony@squid-vision.com> Date: Thu, 19 Jul 2012 09:36:33 -0300 Subject: [media] bttv: add support for Aposonic W-DVR Forwarded-by: Gerd Hoffmann <kraxel@bytesex.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- Documentation/video4linux/CARDLIST.bttv | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/video4linux') diff --git a/Documentation/video4linux/CARDLIST.bttv b/Documentation/video4linux/CARDLIST.bttv index b753906..581f666 100644 --- a/Documentation/video4linux/CARDLIST.bttv +++ b/Documentation/video4linux/CARDLIST.bttv @@ -159,3 +159,4 @@ 158 -> Geovision GV-800(S) (slave) [800b:763d,800c:763d,800d:763d] 159 -> ProVideo PV183 [1830:1540,1831:1540,1832:1540,1833:1540,1834:1540,1835:1540,1836:1540,1837:1540] 160 -> Tongwei Video Technology TD-3116 [f200:3116] +161 -> Aposonic W-DVR [0279:0228] -- cgit v1.1 From d1b4a085fbd31d182a19f8a0c5144e4f5e831b8a Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab <mchehab@redhat.com> Date: Mon, 30 Jul 2012 23:10:38 -0300 Subject: [media] Documentation: Update cardlists Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> --- Documentation/video4linux/CARDLIST.au0828 | 2 +- Documentation/video4linux/CARDLIST.cx23885 | 4 +++- Documentation/video4linux/CARDLIST.saa7134 | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) (limited to 'Documentation/video4linux') diff --git a/Documentation/video4linux/CARDLIST.au0828 b/Documentation/video4linux/CARDLIST.au0828 index 7b59e95..a8a6575 100644 --- a/Documentation/video4linux/CARDLIST.au0828 +++ b/Documentation/video4linux/CARDLIST.au0828 @@ -3,4 +3,4 @@ 2 -> Hauppauge HVR850 (au0828) [2040:7240] 3 -> DViCO FusionHDTV USB (au0828) [0fe9:d620] 4 -> Hauppauge HVR950Q rev xxF8 (au0828) [2040:7201,2040:7211,2040:7281] - 5 -> Hauppauge Woodbury (au0828) [2040:8200] + 5 -> Hauppauge Woodbury (au0828) [05e1:0480,2040:8200] diff --git a/Documentation/video4linux/CARDLIST.cx23885 b/Documentation/video4linux/CARDLIST.cx23885 index f316d18..652aecd 100644 --- a/Documentation/video4linux/CARDLIST.cx23885 +++ b/Documentation/video4linux/CARDLIST.cx23885 @@ -18,7 +18,7 @@ 17 -> NetUP Dual DVB-S2 CI [1b55:2a2c] 18 -> Hauppauge WinTV-HVR1270 [0070:2211] 19 -> Hauppauge WinTV-HVR1275 [0070:2215,0070:221d,0070:22f2] - 20 -> Hauppauge WinTV-HVR1255 [0070:2251,0070:2259,0070:22f1] + 20 -> Hauppauge WinTV-HVR1255 [0070:2251,0070:22f1] 21 -> Hauppauge WinTV-HVR1210 [0070:2291,0070:2295,0070:2299,0070:229d,0070:22f0,0070:22f3,0070:22f4,0070:22f5] 22 -> Mygica X8506 DMB-TH [14f1:8651] 23 -> Magic-Pro ProHDTV Extreme 2 [14f1:8657] @@ -33,3 +33,5 @@ 32 -> MPX-885 33 -> Mygica X8507 [14f1:8502] 34 -> TerraTec Cinergy T PCIe Dual [153b:117e] + 35 -> TeVii S471 [d471:9022] + 36 -> Hauppauge WinTV-HVR1255 [0070:2259] diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134 index 34f3b33..94d9025 100644 --- a/Documentation/video4linux/CARDLIST.saa7134 +++ b/Documentation/video4linux/CARDLIST.saa7134 @@ -188,3 +188,4 @@ 187 -> Beholder BeholdTV 503 FM [5ace:5030] 188 -> Sensoray 811/911 [6000:0811,6000:0911] 189 -> Kworld PC150-U [17de:a134] +190 -> Asus My Cinema PS3-100 [1043:48cd] -- cgit v1.1