serial: timbuart: make sure last byte is sent when port is closed

Fix a problem in early versions of the FPGA IP.

In certain situations the IP reports that the FIFO is empty, but a byte is
still clocked out.  If a flush is done at that point the currently clocked
byte is canceled.

This causes incompatibilities with the upper layers when a port is closed,
it waits until the FIFO is empty and then closes the port.  During close
the FIFO is flushed -> the last byte is not sent properly.

Now the FIFO is only flushed if it is reported to be non-empty.  Which
makes the currently clocked out byte to finish.

[[email protected]: fix build]
Signed-off-by: Richard Röjfors <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions