diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/userp.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/userp.rst | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/media/uapi/v4l/userp.rst b/Documentation/media/uapi/v4l/userp.rst index dc2893a60d65..e25715a2c6fa 100644 --- a/Documentation/media/uapi/v4l/userp.rst +++ b/Documentation/media/uapi/v4l/userp.rst @@ -62,9 +62,9 @@ memory pages at any time between the completion of the DMA and this ioctl. The memory is also unlocked when :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` is called, :ref:`VIDIOC_REQBUFS`, or when the device is closed. -Applications must take care not to free buffers without dequeuing. For -once, the buffers remain locked until further, wasting physical memory. -Second the driver will not be notified when the memory is returned to +Applications must take care not to free buffers without dequeuing. +Firstly, the buffers remain locked for longer, wasting physical memory. +Secondly the driver will not be notified when the memory is returned to the application's free list and subsequently reused for other purposes, possibly completing the requested DMA and overwriting valuable data. @@ -90,7 +90,7 @@ To start and stop capturing or output applications call the .. note:: - ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` removes all buffers from + :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` removes all buffers from both queues and unlocks all buffers as a side effect. Since there is no notion of doing anything "now" on a multitasking system, if an application needs to synchronize with another event it should examine |