1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
index a3b1af7b6db9..a4932387bbfb 100644
--- a/Documentation/serial/serial-rs485.txt
+++ b/Documentation/serial/serial-rs485.txt
@@ -11,10 +11,11 @@
 2. HARDWARE-RELATED CONSIDERATIONS
-   Some CPUs (e.g., Atmel AT91) contain a built-in half-duplex mode capable of
+   Some CPUs/UARTs (e.g., Atmel AT91 or 16C950 UART) contain a built-in
-   automatically controlling line direction by toggling RTS. That can used to
+   half-duplex mode capable of automatically controlling line direction by
-   control external half-duplex hardware like an RS485 transceiver or any
+   toggling RTS or DTR signals. That can be used to control external
-   RS232-connected half-duplex device like some modems.
+   half-duplex hardware like an RS485 transceiver or any RS232-connected
+   half-duplex devices like some modems.
   For these microcontrollers, the Linux driver should be made capable of
   working in both modes, and proper ioctls (see later) should be made

diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt index a3b1af7b6db9..a4932387bbfb 100644 --- a/Documentation/serial/serial-rs485.txt +++ b/Documentation/serial/serial-rs485.txt
@@ -11,10 +11,11 @@
11		11
12	2. HARDWARE-RELATED CONSIDERATIONS	12	2. HARDWARE-RELATED CONSIDERATIONS
13		13
14	Some CPUs (e.g., Atmel AT91) contain a built-in half-duplex mode capable of	14	Some CPUs/UARTs (e.g., Atmel AT91 or 16C950 UART) contain a built-in
15	automatically controlling line direction by toggling RTS. That can used to	15	half-duplex mode capable of automatically controlling line direction by
16	control external half-duplex hardware like an RS485 transceiver or any	16	toggling RTS or DTR signals. That can be used to control external
17	RS232-connected half-duplex device like some modems.	17	half-duplex hardware like an RS485 transceiver or any RS232-connected
		18	half-duplex devices like some modems.
18		19
19	For these microcontrollers, the Linux driver should be made capable of	20	For these microcontrollers, the Linux driver should be made capable of
20	working in both modes, and proper ioctls (see later) should be made	21	working in both modes, and proper ioctls (see later) should be made