Merge tag 'tty-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial driver fixes from Greg KH:
 "Here are some TTY and Serial driver fixes for 5.19-rc7. They resolve a
  number of reported problems including:

   - longtime bug in pty_write() that has been reported in the past.

   - 8250 driver fixes

   - new serial device ids

   - vt overlapping data copy bugfix

   - other tiny serial driver bugfixes

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

* tag 'tty-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: use new tty_insert_flip_string_and_push_buffer() in pty_write()
  tty: extract tty_flip_buffer_commit() from tty_flip_buffer_push()
  serial: 8250: dw: Fix the macro RZN1_UART_xDMACR_8_WORD_BURST
  vt: fix memory overlapping when deleting chars in the buffer
  serial: mvebu-uart: correctly report configured baudrate value
  serial: 8250: Fix PM usage_count for console handover
  serial: 8250: fix return error code in serial8250_request_std_resource()
  serial: stm32: Clear prev values before setting RTS delays
  tty: Add N_CAN327 line discipline ID for ELM327 based CAN driver
  serial: 8250: Fix __stop_tx() & DMA Tx restart races
  serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle
  tty: serial: samsung_tty: set dma burst_size to 1
  serial: 8250: dw: enable using pdata with ACPI

drivers/tty/pty.c

@@ -111,21 +111,11 @@ static void pty_unthrottle(struct tty_struct *tty)
 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
 {
 	struct tty_struct *to = tty->link;
-	unsigned long flags;
 
-	if (tty->flow.stopped)
+	if (tty->flow.stopped || !c)
 		return 0;
 
-	if (c > 0) {
-		spin_lock_irqsave(&to->port->lock, flags);
-		/* Stuff the data into the input queue of the other end */
-		c = tty_insert_flip_string(to->port, buf, c);
-		spin_unlock_irqrestore(&to->port->lock, flags);
-		/* And shovel */
-		if (c)
-			tty_flip_buffer_push(to->port);
-	}
-	return c;
+	return tty_insert_flip_string_and_push_buffer(to->port, buf, c);
 }
 
 /**

drivers/tty/serial/8250/8250_core.c

@@ -23,6 +23,7 @@
 #include <linux/sysrq.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/tty.h>
 #include <linux/ratelimit.h>
 #include <linux/tty_flip.h>
@@ -559,6 +560,9 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 
 		up->port.dev = dev;
 
+		if (uart_console_enabled(&up->port))
+			pm_runtime_get_sync(up->port.dev);
+
 		serial8250_apply_quirks(up);
 		uart_add_one_port(drv, &up->port);
 	}

drivers/tty/serial/8250/8250_dma.c

@@ -106,10 +106,10 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 				   UART_XMIT_SIZE, DMA_TO_DEVICE);
 
 	dma_async_issue_pending(dma->txchan);
-	if (dma->tx_err) {
+	serial8250_clear_THRI(p);
+	if (dma->tx_err)
 		dma->tx_err = 0;
-		serial8250_clear_THRI(p);
-	}
+
 	return 0;
 err:
 	dma->tx_err = 1;

drivers/tty/serial/8250/8250_dw.c

@@ -47,7 +47,7 @@
 #define RZN1_UART_xDMACR_DMA_EN		BIT(0)
 #define RZN1_UART_xDMACR_1_WORD_BURST	(0 << 1)
 #define RZN1_UART_xDMACR_4_WORD_BURST	(1 << 1)
-#define RZN1_UART_xDMACR_8_WORD_BURST	(3 << 1)
+#define RZN1_UART_xDMACR_8_WORD_BURST	(2 << 1)
 #define RZN1_UART_xDMACR_BLK_SZ(x)	((x) << 3)
 
 /* Quirks */
@@ -773,18 +773,18 @@ static const struct of_device_id dw8250_of_match[] = {
 MODULE_DEVICE_TABLE(of, dw8250_of_match);
 
 static const struct acpi_device_id dw8250_acpi_match[] = {
-	{ "INT33C4", 0 },
-	{ "INT33C5", 0 },
-	{ "INT3434", 0 },
-	{ "INT3435", 0 },
-	{ "80860F0A", 0 },
-	{ "8086228A", 0 },
-	{ "APMC0D08", 0},
-	{ "AMD0020", 0 },
-	{ "AMDI0020", 0 },
-	{ "AMDI0022", 0 },
-	{ "BRCM2032", 0 },
-	{ "HISI0031", 0 },
+	{ "80860F0A", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "8086228A", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMD0020", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMDI0020", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "AMDI0022", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "APMC0D08", (kernel_ulong_t)&dw8250_dw_apb},
+	{ "BRCM2032", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "HISI0031", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT33C4", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT33C5", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT3434", (kernel_ulong_t)&dw8250_dw_apb },
+	{ "INT3435", (kernel_ulong_t)&dw8250_dw_apb },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);

drivers/tty/serial/8250/8250_port.c

@@ -1949,7 +1949,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	if ((status & UART_LSR_THRE) && (up->ier & UART_IER_THRI)) {
 		if (!up->dma || up->dma->tx_err)
 			serial8250_tx_chars(up);
-		else
+		else if (!up->dma->tx_running)
 			__stop_tx(up);
 	}
 
@@ -2975,8 +2975,10 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 	case UPIO_MEM32BE:
 	case UPIO_MEM16:
 	case UPIO_MEM:
-		if (!port->mapbase)
+		if (!port->mapbase) {
+			ret = -EINVAL;
 			break;
+		}
 
 		if (!request_mem_region(port->mapbase, size, "serial")) {
 			ret = -EBUSY;

drivers/tty/serial/amba-pl011.c

@@ -1367,6 +1367,15 @@ static void pl011_stop_rx(struct uart_port *port)
 	pl011_dma_rx_stop(uap);
 }
 
+static void pl011_throttle_rx(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	pl011_stop_rx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
 static void pl011_enable_ms(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
@@ -1788,9 +1797,10 @@ static int pl011_allocate_irq(struct uart_amba_port *uap)
  */
 static void pl011_enable_interrupts(struct uart_amba_port *uap)
 {
+	unsigned long flags;
 	unsigned int i;
 
-	spin_lock_irq(&uap->port.lock);
+	spin_lock_irqsave(&uap->port.lock, flags);
 
 	/* Clear out any spuriously appearing RX interrupts */
 	pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
@@ -1812,7 +1822,14 @@ static void pl011_enable_interrupts(struct uart_amba_port *uap)
 	if (!pl011_dma_rx_running(uap))
 		uap->im |= UART011_RXIM;
 	pl011_write(uap->im, uap, REG_IMSC);
-	spin_unlock_irq(&uap->port.lock);
+	spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static void pl011_unthrottle_rx(struct uart_port *port)
+{
+	struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
+
+	pl011_enable_interrupts(uap);
 }
 
 static int pl011_startup(struct uart_port *port)
@@ -2225,6 +2242,8 @@ static const struct uart_ops amba_pl011_pops = {
 	.stop_tx	= pl011_stop_tx,
 	.start_tx	= pl011_start_tx,
 	.stop_rx	= pl011_stop_rx,
+	.throttle	= pl011_throttle_rx,
+	.unthrottle	= pl011_unthrottle_rx,
 	.enable_ms	= pl011_enable_ms,
 	.break_ctl	= pl011_break_ctl,
 	.startup	= pl011_startup,

drivers/tty/serial/mvebu-uart.c

@@ -470,14 +470,14 @@ static void mvebu_uart_shutdown(struct uart_port *port)
 	}
 }
 
-static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
+static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
 {
 	unsigned int d_divisor, m_divisor;
 	unsigned long flags;
 	u32 brdv, osamp;
 
 	if (!port->uartclk)
-		return -EOPNOTSUPP;
+		return 0;
 
 	/*
 	 * The baudrate is derived from the UART clock thanks to divisors:
@@ -548,7 +548,7 @@ static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
 			(m_divisor << 16) | (m_divisor << 24);
 	writel(osamp, port->membase + UART_OSAMP);
 
-	return 0;
+	return DIV_ROUND_CLOSEST(port->uartclk, d_divisor * m_divisor);
 }
 
 static void mvebu_uart_set_termios(struct uart_port *port,
@@ -587,15 +587,11 @@ static void mvebu_uart_set_termios(struct uart_port *port,
 	max_baud = port->uartclk / 80;
 
 	baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud);
-	if (mvebu_uart_baud_rate_set(port, baud)) {
-		/* No clock available, baudrate cannot be changed */
-		if (old)
-			baud = uart_get_baud_rate(port, old, NULL,
-						  min_baud, max_baud);
-	} else {
-		tty_termios_encode_baud_rate(termios, baud, baud);
-		uart_update_timeout(port, termios->c_cflag, baud);
-	}
+	baud = mvebu_uart_baud_rate_set(port, baud);
+
+	/* In case baudrate cannot be changed, report previous old value */
+	if (baud == 0 && old)
+		baud = tty_termios_baud_rate(old);
 
 	/* Only the following flag changes are supported */
 	if (old) {
@@ -606,6 +602,11 @@ static void mvebu_uart_set_termios(struct uart_port *port,
 		termios->c_cflag |= CS8;
 	}
 
+	if (baud != 0) {
+		tty_termios_encode_baud_rate(termios, baud, baud);
+		uart_update_timeout(port, termios->c_cflag, baud);
+	}
+
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 

drivers/tty/serial/samsung_tty.c

@@ -377,8 +377,7 @@ static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
 	/* Enable tx dma mode */
 	ucon = rd_regl(port, S3C2410_UCON);
 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
-	ucon |= (dma_get_cache_alignment() >= 16) ?
-		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
+	ucon |= S3C64XX_UCON_TXBURST_1;
 	ucon |= S3C64XX_UCON_TXMODE_DMA;
 	wr_regl(port,  S3C2410_UCON, ucon);
 
@@ -674,7 +673,7 @@ static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
 			S3C64XX_UCON_DMASUS_EN |
 			S3C64XX_UCON_TIMEOUT_EN |
 			S3C64XX_UCON_RXMODE_MASK);
-	ucon |= S3C64XX_UCON_RXBURST_16 |
+	ucon |= S3C64XX_UCON_RXBURST_1 |
 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
 			S3C64XX_UCON_EMPTYINT_EN |
 			S3C64XX_UCON_TIMEOUT_EN |

drivers/tty/serial/serial_core.c

@@ -1941,11 +1941,6 @@ static int uart_proc_show(struct seq_file *m, void *v)
 }
 #endif
 
-static inline bool uart_console_enabled(struct uart_port *port)
-{
-	return uart_console(port) && (port->cons->flags & CON_ENABLED);
-}
-
 static void uart_port_spin_lock_init(struct uart_port *port)
 {
 	spin_lock_init(&port->lock);

drivers/tty/serial/stm32-usart.c

@@ -72,6 +72,8 @@ static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
 	*cr3 |= USART_CR3_DEM;
 	over8 = *cr1 & USART_CR1_OVER8;
 
+	*cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);
+
 	if (over8)
 		rs485_deat_dedt = delay_ADE * baud * 8;
 	else

drivers/tty/tty.h

@@ -111,4 +111,7 @@ static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 
 ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
 
+int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
+		const unsigned char *chars, size_t cnt);
+
 #endif

drivers/tty/tty_buffer.c

@@ -532,6 +532,15 @@ static void flush_to_ldisc(struct work_struct *work)
 
 }
 
+static inline void tty_flip_buffer_commit(struct tty_buffer *tail)
+{
+	/*
+	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
+	 * buffer data.
+	 */
+	smp_store_release(&tail->commit, tail->used);
+}
+
 /**
  * tty_flip_buffer_push		-	push terminal buffers
  * @port: tty port to push
@@ -546,15 +555,42 @@ void tty_flip_buffer_push(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
 
-	/*
-	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
-	 * buffer data.
-	 */
-	smp_store_release(&buf->tail->commit, buf->tail->used);
+	tty_flip_buffer_commit(buf->tail);
 	queue_work(system_unbound_wq, &buf->work);
 }
 EXPORT_SYMBOL(tty_flip_buffer_push);
 
+/**
+ * tty_insert_flip_string_and_push_buffer - add characters to the tty buffer and
+ *	push
+ * @port: tty port
+ * @chars: characters
+ * @size: size
+ *
+ * The function combines tty_insert_flip_string() and tty_flip_buffer_push()
+ * with the exception of properly holding the @port->lock.
+ *
+ * To be used only internally (by pty currently).
+ *
+ * Returns: the number added.
+ */
+int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
+		const unsigned char *chars, size_t size)
+{
+	struct tty_bufhead *buf = &port->buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	size = tty_insert_flip_string(port, chars, size);
+	if (size)
+		tty_flip_buffer_commit(buf->tail);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	queue_work(system_unbound_wq, &buf->work);
+
+	return size;
+}
+
 /**
  * tty_buffer_init		-	prepare a tty buffer structure
  * @port: tty port to initialise

drivers/tty/vt/vt.c

@@ -855,7 +855,7 @@ static void delete_char(struct vc_data *vc, unsigned int nr)
 	unsigned short *p = (unsigned short *) vc->vc_pos;
 
 	vc_uniscr_delete(vc, nr);
-	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
+	scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 	scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
 			nr * 2);
 	vc->vc_need_wrap = 0;

include/linux/serial_core.h

@@ -390,6 +390,11 @@ static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
 static inline int setup_earlycon(char *buf) { return 0; }
 #endif
 
+static inline bool uart_console_enabled(struct uart_port *port)
+{
+	return uart_console(port) && (port->cons->flags & CON_ENABLED);
+}
+
 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
 				   struct console *c);
 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,

include/uapi/linux/tty.h

@@ -38,8 +38,9 @@
 #define N_NULL		27	/* Null ldisc used for error handling */
 #define N_MCTP		28	/* MCTP-over-serial */
 #define N_DEVELOPMENT	29	/* Manual out-of-tree testing */
+#define N_CAN327	30	/* ELM327 based OBD-II interfaces */
 
 /* Always the newest line discipline + 1 */
-#define NR_LDISCS	30
+#define NR_LDISCS	31
 
 #endif /* _UAPI_LINUX_TTY_H */