Our partner have a question about i.MX6S V4L2 driver of L3.0.35_4.1.0 BSP.
They understand the timing that V4L2 driver receive data as following.
A buffer which is enqueued to driver by VIDIOC_QBUF have two status.
These are V4L2_BUF_FLAG_QUEUED and V4L2_BUF_FLAG_DONE.
And it will be able to be dequeued (be able to write a next data to input buffer which was enqueued in previous step) when V4L2_BUF_FLAG_DONE sutatus.
However, according to the source code (comment around line 743 in drivers/media/video/mxc/output/mxc_vout.c), the first buffer can be dequeued after 3 buffers is enqueued if input buffer size = output buffer size.
In this case, can our partner check whether the next data can be written to the first buffer before the 3rd buffer is enqueued?