Valentin Longchamp wrote:

First I wanted to fix the fact that the imx serial hardware only raises 
the CTS pin when the oferflowing char begins to be set. I would have 
solved this by setting the CTS trigger value to 31 instead of 32. But 
when I talked with one colleague he told me about 16550A (that is 
present nearly everywhere) that empty their TX FIFO, so I lowered it to 16.

That seems quite peculiar because a 16550A only has a 16 byte receive
buffer, doesn't it?  And therefore it would have trouble talking
reliably to another 16550A if it worked like that.  I wonder what I'm
not seeing in this picture.

-- Jamie