[PATCH v2 3/4] man/man3/termios.3: document that output baud rate has priority

Many devices, including the good old 8250 series UARTs, cannot handle
different input and output baud rates. POSIX defines the output rate
as taking priority, and Linux follows this. Explicitly document this.

Signed-off-by: H. Peter Anvin <[email protected]>
---
 man/man3/termios.3 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/man/man3/termios.3 b/man/man3/termios.3
index f563923fc7cf..84b10cb7d68c 100644
--- a/man/man3/termios.3
+++ b/man/man3/termios.3
@@ -1127,6 +1127,10 @@ The input and output baud rates are stored in the
 .I termios
 structure.
 .P
+If a certain device does not support different input and output
+baud rates, the output baud rate is used for both if they are
+programmed to be different.
+.P
 .BR cfgetospeed ()
 and
 .BR cfgetobaud ()
-- 
2.54.0