Commit 4b2981b2 authored Feb 17, 2024 by Linus Torvalds

Merge tag 'tty-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial fixes from Greg KH:
 "Here are three small tty and serial driver fixes for 6.8-rc5:

   - revert a 8250_pci1xxxx off-by-one change that was incorrect

   - two changes to fix the transmit path of the mxs-auart driver,
     fixing a regression in the 6.2 release

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

* tag 'tty-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: mxs-auart: fix tx
  serial: core: introduce uart_port_tx_flags()
  serial: 8250_pci1xxxx: partially revert off by one patch

parents a3a7d162 7be50f2e

drivers/tty/serial/8250/8250_pci1xxxx.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -302,7 +302,7 @@ static void pci1xxxx_process_read_data(struct uart_port *port,
		* to read, the data is received one byte at a time.
		*/
		while (valid_burst_count--) {
		if (*buff_index >= (RX_BUF_SIZE - UART_BURST_SIZE))
		if (*buff_index > (RX_BUF_SIZE - UART_BURST_SIZE))
		break;
		burst_buf = (u32 )&rx_buff[buff_index];
		*burst_buf = readl(port->membase + UART_RX_BURST_FIFO);

drivers/tty/serial/mxs-auart.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -605,13 +605,16 @@ static void mxs_auart_tx_chars(struct mxs_auart_port *s)
		return;
		}

		pending = uart_port_tx(&s->port, ch,
		pending = uart_port_tx_flags(&s->port, ch, UART_TX_NOSTOP,
		!(mxs_read(s, REG_STAT) & AUART_STAT_TXFF),
		mxs_write(ch, s, REG_DATA));
		if (pending)
		mxs_set(AUART_INTR_TXIEN, s, REG_INTR);
		else
		mxs_clr(AUART_INTR_TXIEN, s, REG_INTR);

		if (uart_tx_stopped(&s->port))
		mxs_auart_stop_tx(&s->port);
		}

		static void mxs_auart_rx_char(struct mxs_auart_port *s)

include/linux/serial_core.h

+27 −5

Original line number	Diff line number	Diff line
		@@ -748,8 +748,17 @@ struct uart_driver {

		void uart_write_wakeup(struct uart_port *port);

		#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test, \
		for_post) \
		/**
		* enum UART_TX_FLAGS -- flags for uart_port_tx_flags()
		*
		* @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer
		*/
		enum UART_TX_FLAGS {
		UART_TX_NOSTOP = BIT(0),
		};

		#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \
		for_test, for_post) \
		({ \
		struct uart_port *__port = (uport); \
		struct circ_buf *xmit = &__port->state->xmit; \
		@@ -777,7 +786,7 @@ void uart_write_wakeup(struct uart_port *port);
		if (pending < WAKEUP_CHARS) { \
		uart_write_wakeup(__port); \
		\
		if (pending == 0) \
		if (!((flags) & UART_TX_NOSTOP) && pending == 0) \
		__port->ops->stop_tx(__port); \
		} \
		\
		@@ -812,7 +821,7 @@ void uart_write_wakeup(struct uart_port *port);
		*/
		#define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \
		unsigned int __count = (count); \
		__uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count, \
		__uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \
		__count--); \
		})

		@@ -826,8 +835,21 @@ void uart_write_wakeup(struct uart_port *port);
		* See uart_port_tx_limited() for more details.
		*/
		#define uart_port_tx(port, ch, tx_ready, put_char) \
		__uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({}))
		__uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))


		/**
		* uart_port_tx_flags -- transmit helper for uart_port with flags
		* @port: uart port
		* @ch: variable to store a character to be written to the HW
		* @flags: %UART_TX_NOSTOP or similar
		* @tx_ready: can HW accept more data function
		* @put_char: function to write a character
		*
		* See uart_port_tx_limited() for more details.
		*/
		#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \
		__uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))
		/*
		* Baud rate helpers.
		*/