tree 617a186a73de93d8d81fa2c808584e1642288114
parent 3d23b4c364e6fca720bf68655248c16c498e36f3
author Baruch Siach <baruch@tkos.co.il> 1456749250 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1462033615 -0700

serial: imx: support RS-485 Rx disable on Tx

Some RS-232 to RS-485 transceivers require Rx to be disabled on Tx to
avoid echo of Tx data into the Rx buffer. Specifically, the XR3160E
RS-232/RS-485/RS-422 transceiver behaves this way.

This commit disables Rx on active Tx when SER_RS485_ENABLED is active and
SER_RS485_RX_DURING_TX is disabled.

Note that this is a change in behavior of the driver. Until now
SER_RS485_RX_DURING_TX was enabled unconditionally even when disabled in
the TIOCSRS485 ioctl serial_rs485 flags field.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>