linux-wandboard

MLK-16205 video: fbdev: dcss: handle cfifo wrapping case

As time goes on, the cfifo buffer is close to be
exausted. And since the cfifo is a ring buffer,
so at this moment, the cfifo needs to be wrapped
to the buffer beginning. In this driver, the fifo
wrapping condition is that the free size to buffer
end is less than the commit size. And before the
buffer wrapping, the 'ctxld_wq' workqueue needs to
be flushed to make sure all the previous commited
jobs to be finished. Besides, this commit uses the
spinlock in the 'cqueue' workqueue to replace the
'wlock'.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>