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02f142ecd2
If start_streaming returns -ENOBUFS, then it will be retried the next time a buffer is queued. This means applications no longer need to know how many buffers need to be queued before STREAMON can be called. This is particularly useful for output stream I/O. If a DMA engine needs at least X buffers before it can start streaming, then for applications to get a buffer out as soon as possible they need to know the minimum number of buffers to queue before STREAMON can be called. You can't just try STREAMON after every buffer since on failure STREAMON will dequeue all your buffers. (Is that a bug or a feature? Frankly, I'm not sure). This patch simplifies applications substantially: they can just call STREAMON at the beginning and then start queuing buffers and the DMA engine will kick in automagically once enough buffers are available. This also fixes using write() to stream video: the fileio implementation calls streamon without having any queued buffers, which will fail today for any driver that requires a minimum number of buffers. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> |
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| .. | ||
| common | ||
| dvb-core | ||
| dvb-frontends | ||
| firewire | ||
| i2c | ||
| mmc | ||
| parport | ||
| pci | ||
| platform | ||
| radio | ||
| rc | ||
| tuners | ||
| usb | ||
| v4l2-core | ||
| Kconfig | ||
| Makefile | ||
| media-device.c | ||
| media-devnode.c | ||
| media-entity.c | ||