Merge tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the "big" set of tty/serial driver changes for 6.2-rc1.

  As in previous kernel releases, nothing big here at all, just some
  small incremental serial/tty layer cleanups and some individual driver
  additions and fixes. Highlights are:

   - serial helper macros from Jiri Slaby to reduce the amount of
     duplicated code in serial drivers

   - api cleanups and consolidations from Ilpo Järvinen in lots of
     serial drivers

   - the usual set of n_gsm fixes from Daniel Starke as that code gets
     exercised more

   - TIOCSTI is finally able to be disabled if requested (security
     hardening feature from Kees Cook)

   - fsl_lpuart driver fixes and features added

   - other small serial driver additions and fixes

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

* tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits)
  serial: atmel: don't stop the transmitter when doing PIO
  serial: atmel: cleanup atmel_start+stop_tx()
  tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API
  serial: sunsab: Fix error handling in sunsab_init()
  serial: altera_uart: fix locking in polling mode
  serial: pch: Fix PCI device refcount leak in pch_request_dma()
  tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused
  tty: serial: fsl_lpuart: Add runtime pm support
  tty: serial: fsl_lpuart: enable wakeup source for lpuart
  serdev: Replace poll loop by readx_poll_timeout() macro
  tty: synclink_gt: unwind actions in error path of net device open
  serial: stm32: move dma_request_chan() before clk_prepare_enable()
  dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity'
  serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
  serial: amba-pl011: avoid SBSA UART accessing DMACR register
  tty: serial: altera_jtaguart: remove struct altera_jtaguart
  tty: serial: altera_jtaguart: use uart_port::read_status_mask
  tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs
  tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()
  n_tty: Rename tail to old_tail in n_tty_read()
  ...

1 files changed, 32 insertions, 48 deletions

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index bd07f79a2df9..f1c06e12efa0 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -552,19 +552,23 @@ static u_int atmel_get_mctrl(struct uart_port *port)
 static void atmel_stop_tx(struct uart_port *port)
 {
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool is_pdc = atmel_use_pdc_tx(port);
+	bool is_dma = is_pdc || atmel_use_dma_tx(port);
 
-	if (atmel_use_pdc_tx(port)) {
+	if (is_pdc) {
 		/* disable PDC transmit */
 		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS);
 	}
 
-	/*
-	 * Disable the transmitter.
-	 * This is mandatory when DMA is used, otherwise the DMA buffer
-	 * is fully transmitted.
-	 */
-	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS);
-	atmel_port->tx_stopped = true;
+	if (is_dma) {
+		/*
+		 * Disable the transmitter.
+		 * This is mandatory when DMA is used, otherwise the DMA buffer
+		 * is fully transmitted.
+		 */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS);
+		atmel_port->tx_stopped = true;
+	}
 
 	/* Disable interrupts */
 	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
@@ -572,7 +576,6 @@ static void atmel_stop_tx(struct uart_port *port)
 	if (atmel_uart_is_half_duplex(port))
 		if (!atomic_read(&atmel_port->tasklet_shutdown))
 			atmel_start_rx(port);
-
 }
 
 /*
@@ -581,27 +584,31 @@ static void atmel_stop_tx(struct uart_port *port)
 static void atmel_start_tx(struct uart_port *port)
 {
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool is_pdc = atmel_use_pdc_tx(port);
+	bool is_dma = is_pdc || atmel_use_dma_tx(port);
 
-	if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR)
+	if (is_pdc && (atmel_uart_readl(port, ATMEL_PDC_PTSR)
 				       & ATMEL_PDC_TXTEN))
 		/* The transmitter is already running.  Yes, we
 		   really need this.*/
 		return;
 
-	if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
-		if (atmel_uart_is_half_duplex(port))
-			atmel_stop_rx(port);
+	if (is_dma && atmel_uart_is_half_duplex(port))
+		atmel_stop_rx(port);
 
-	if (atmel_use_pdc_tx(port))
+	if (is_pdc) {
 		/* re-enable PDC transmit */
 		atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
+	}
 
 	/* Enable interrupts */
 	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
 
-	/* re-enable the transmitter */
-	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);
-	atmel_port->tx_stopped = false;
+	if (is_dma) {
+		/* re-enable the transmitter */
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);
+		atmel_port->tx_stopped = false;
+	}
 }
 
 /*
@@ -824,30 +831,14 @@ static void atmel_rx_chars(struct uart_port *port)
  */
 static void atmel_tx_chars(struct uart_port *port)
 {
-	struct circ_buf *xmit = &port->state->xmit;
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	bool pending;
+	u8 ch;
 
-	if (port->x_char &&
-	    (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;
-	}
-	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
-		return;
-
-	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++;
-		if (uart_circ_empty(xmit))
-			break;
-	}
-
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-		uart_write_wakeup(port);
-
-	if (!uart_circ_empty(xmit)) {
+	pending = uart_port_tx(port, ch,
+		atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY,
+		atmel_uart_write_char(port, ch));
+	if (pending) {
 		/* we still have characters to transmit, so we should continue
 		 * transmitting them when TX is ready, regardless of
 		 * mode or duplexity
@@ -875,10 +866,7 @@ static void atmel_complete_tx_dma(void *arg)
 
 	if (chan)
 		dmaengine_terminate_all(chan);
-	xmit->tail += atmel_port->tx_len;
-	xmit->tail &= UART_XMIT_SIZE - 1;
-
-	port->icount.tx += atmel_port->tx_len;
+	uart_xmit_advance(port, atmel_port->tx_len);
 
 	spin_lock_irq(&atmel_port->lock_tx);
 	async_tx_ack(atmel_port->desc_tx);
@@ -1471,11 +1459,7 @@ static void atmel_tx_pdc(struct uart_port *port)
 	/* nothing left to transmit? */
 	if (atmel_uart_readl(port, ATMEL_PDC_TCR))
 		return;
-
-	xmit->tail += pdc->ofs;
-	xmit->tail &= UART_XMIT_SIZE - 1;
-
-	port->icount.tx += pdc->ofs;
+	uart_xmit_advance(port, pdc->ofs);
 	pdc->ofs = 0;
 
 	/* more to transmit - setup next transfer */