From: Dimitris Lampridis Date: Thu, 13 Mar 2014 13:11:46 +0000 (+0200) Subject: tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX X-Git-Tag: firefly_0821_release~176^2~4192^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cab53dc9e20f74fbd4776ea584ba3b21c957b1a8;p=firefly-linux-kernel-4.4.55.git tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX Make sure that serial_omap_stop_rx() also disables RDI (Receiver Data Interrupt), otherwise the interrupt handler will call serial_omap_rdi() to read the new data, resulting in the transmission being echoed back. When the half-duplex transmission is complete, in order to reverse the effects of serial_omap_stop_rx(), we should re-enable: * the RX interrupts _without_ overwriting up->ier * the UART_LSR_DR bit of the up->port.read_status_mask Signed-off-by: Dimitris Lampridis Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 77f035158d6c..65abea2c6e47 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -342,7 +342,8 @@ static void serial_omap_stop_tx(struct uart_port *port) if ((up->rs485.flags & SER_RS485_ENABLED) && !(up->rs485.flags & SER_RS485_RX_DURING_TX)) { - up->ier = UART_IER_RLSI | UART_IER_RDI; + up->ier |= UART_IER_RLSI | UART_IER_RDI; + up->port.read_status_mask |= UART_LSR_DR; serial_out(up, UART_IER, up->ier); } @@ -355,7 +356,7 @@ static void serial_omap_stop_rx(struct uart_port *port) struct uart_omap_port *up = to_uart_omap_port(port); pm_runtime_get_sync(up->dev); - up->ier &= ~UART_IER_RLSI; + up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; serial_out(up, UART_IER, up->ier); pm_runtime_mark_last_busy(up->dev);