Merge tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here are the big set of tty and serial driver updates for 5.6-rc1

  Included in here are:
   - dummy_con cleanups (touches lots of arch code)
   - sysrq logic cleanups (touches lots of serial drivers)
   - samsung driver fixes (wasn't really being built)
   - conmakeshash move to tty subdir out of scripts
   - lots of small tty/serial driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
  tty: n_hdlc: Use flexible-array member and struct_size() helper
  tty: baudrate: SPARC supports few more baud rates
  tty: baudrate: Synchronise baud_table[] and baud_bits[]
  tty: serial: meson_uart: Add support for kernel debugger
  serial: imx: fix a race condition in receive path
  serial: 8250_bcm2835aux: Document struct bcm2835aux_data
  serial: 8250_bcm2835aux: Use generic remapping code
  serial: 8250_bcm2835aux: Allocate uart_8250_port on stack
  serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFER
  serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFER
  serial: 8250_bcm2835aux: Fix line mismatch on driver unbind
  serial_core: Remove unused member in uart_port
  vt: Correct comment documenting do_take_over_console()
  vt: Delete comment referencing non-existent unbind_con_driver()
  arch/xtensa/setup: Drop dummy_con initialization
  arch/x86/setup: Drop dummy_con initialization
  arch/unicore32/setup: Drop dummy_con initialization
  arch/sparc/setup: Drop dummy_con initialization
  arch/sh/setup: Drop dummy_con initialization
  arch/s390/setup: Drop dummy_con initialization
  ...

1 files changed, 23 insertions, 18 deletions

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 1ba9bc667e13..c15c398c88a9 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -51,10 +51,6 @@
 #define ATMEL_RTS_HIGH_OFFSET	16
 #define ATMEL_RTS_LOW_OFFSET	20
 
-#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/serial_core.h>
 
 #include "serial_mctrl_gpio.h"
@@ -196,10 +192,6 @@ struct atmel_uart_port {
 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
 static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART);
 
-#ifdef SUPPORT_SYSRQ
-static struct console atmel_console;
-#endif
-
 #if defined(CONFIG_OF)
 static const struct of_device_id atmel_serial_dt_ids[] = {
 	{ .compatible = "atmel,at91rm9200-usart-serial" },
@@ -313,7 +305,11 @@ static int atmel_config_rs485(struct uart_port *port,
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
 		dev_dbg(port->dev, "Setting UART to RS485\n");
-		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+		if (port->rs485.flags & SER_RS485_RX_DURING_TX)
+			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+		else
+			atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+
 		atmel_uart_writel(port, ATMEL_US_TTGR,
 				  rs485conf->delay_rts_after_send);
 		mode |= ATMEL_US_USMODE_RS485;
@@ -831,7 +827,7 @@ static void atmel_tx_chars(struct uart_port *port)
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
 	if (port->x_char &&
-	    (atmel_uart_readl(port, ATMEL_US_CSR) & atmel_port->tx_done_mask)) {
+	    (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY)) {
 		atmel_uart_write_char(port, port->x_char);
 		port->icount.tx++;
 		port->x_char = 0;
@@ -839,8 +835,7 @@ static void atmel_tx_chars(struct uart_port *port)
 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 		return;
 
-	while (atmel_uart_readl(port, ATMEL_US_CSR) &
-	       atmel_port->tx_done_mask) {
+	while (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY) {
 		atmel_uart_write_char(port, xmit->buf[xmit->tail]);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		port->icount.tx++;
@@ -851,10 +846,20 @@ static void atmel_tx_chars(struct uart_port *port)
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
-	if (!uart_circ_empty(xmit))
+	if (!uart_circ_empty(xmit)) {
+		/* we still have characters to transmit, so we should continue
+		 * transmitting them when TX is ready, regardless of
+		 * mode or duplexity
+		 */
+		atmel_port->tx_done_mask |= ATMEL_US_TXRDY;
+
 		/* Enable interrupts */
 		atmel_uart_writel(port, ATMEL_US_IER,
 				  atmel_port->tx_done_mask);
+	} else {
+		if (atmel_uart_is_half_duplex(port))
+			atmel_port->tx_done_mask &= ~ATMEL_US_TXRDY;
+	}
 }
 
 static void atmel_complete_tx_dma(void *arg)
@@ -1067,7 +1072,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port)
 
 chan_err:
 	dev_err(port->dev, "TX channel not available, switch to pio\n");
-	atmel_port->use_dma_tx = 0;
+	atmel_port->use_dma_tx = false;
 	if (atmel_port->chan_tx)
 		atmel_release_tx_dma(port);
 	return -EINVAL;
@@ -1266,7 +1271,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 
 chan_err:
 	dev_err(port->dev, "RX channel not available, switch to pio\n");
-	atmel_port->use_dma_rx = 0;
+	atmel_port->use_dma_rx = false;
 	if (atmel_port->chan_rx)
 		atmel_release_rx_dma(port);
 	return -EINVAL;
@@ -1693,7 +1698,7 @@ static int atmel_prepare_rx_pdc(struct uart_port *port)
 					DMA_FROM_DEVICE);
 				kfree(atmel_port->pdc_rx[0].buf);
 			}
-			atmel_port->use_pdc_rx = 0;
+			atmel_port->use_pdc_rx = false;
 			return -ENOMEM;
 		}
 		pdc->dma_addr = dma_map_single(port->dev,
@@ -2526,8 +2531,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
 	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
 	 * ENDTX|TXBUFE
 	 */
-	if (port->rs485.flags & SER_RS485_ENABLED ||
-	    port->iso7816.flags & SER_ISO7816_ENABLED)
+	if (atmel_uart_is_half_duplex(port))
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
 	else if (atmel_use_pdc_tx(port)) {
 		port->fifosize = PDC_BUFFER_SIZE;
@@ -2878,6 +2882,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	atmel_port = &atmel_ports[ret];
 	atmel_port->backup_imr = 0;
 	atmel_port->uart.line = ret;
+	atmel_port->uart.has_sysrq = IS_ENABLED(CONFIG_SERIAL_ATMEL_CONSOLE);
 	atmel_serial_probe_fifos(atmel_port, pdev);
 
 	atomic_set(&atmel_port->tasklet_shutdown, 0);