The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f3040983132bf3477acd45d2452a906e67c2fec9 Mon Sep 17 00:00:00 2001
From: Razvan Stefanescu <razvan.stefanescu@xxxxxxxxxxxxx>
Date: Tue, 19 Mar 2019 15:20:34 +0200
Subject: [PATCH] tty/serial: atmel: Add is_half_duplex helper
Use a helper function to check that a port needs to use half duplex
communication, replacing several occurrences of multi-line bit checking.
Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@xxxxxxxxxxxxx>
Acked-by: Richard Genoud <richard.genoud@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 41b728d223d1..55ca3416113f 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -231,6 +231,13 @@ static inline void atmel_uart_write_char(struct uart_port *port, u8 value)
__raw_writeb(value, port->membase + ATMEL_US_THR);
}
+static inline int atmel_uart_is_half_duplex(struct uart_port *port)
+{
+ return ((port->rs485.flags & SER_RS485_ENABLED) &&
+ !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+ (port->iso7816.flags & SER_ISO7816_ENABLED);
+}
+
#ifdef CONFIG_SERIAL_ATMEL_PDC
static bool atmel_use_pdc_rx(struct uart_port *port)
{
@@ -608,10 +615,9 @@ static void atmel_stop_tx(struct uart_port *port)
/* Disable interrupts */
atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED)
+ if (atmel_uart_is_half_duplex(port))
atmel_start_rx(port);
+
}
/*
@@ -628,9 +634,7 @@ static void atmel_start_tx(struct uart_port *port)
return;
if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED)
+ if (atmel_uart_is_half_duplex(port))
atmel_stop_rx(port);
if (atmel_use_pdc_tx(port))
@@ -928,9 +932,7 @@ static void atmel_complete_tx_dma(void *arg)
*/
if (!uart_circ_empty(xmit))
atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
- else if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED) {
+ else if (atmel_uart_is_half_duplex(port)) {
/* DMA done, stop TX, start RX for RS485 */
atmel_start_rx(port);
}
@@ -1512,9 +1514,7 @@ static void atmel_tx_pdc(struct uart_port *port)
atmel_uart_writel(port, ATMEL_US_IER,
atmel_port->tx_done_mask);
} else {
- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED) {
+ if (atmel_uart_is_half_duplex(port)) {
/* DMA done, stop TX, start RX for RS485 */
atmel_start_rx(port);
}
