Commit ad5613b9 authored by Hector Martin's avatar Hector Martin Committed by Greg Kroah-Hartman
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tty: serial: samsung_tty: IRQ rework 



* Split out s3c24xx_serial_tx_chars from s3c24xx_serial_tx_irq,
  where only the latter acquires the port lock. This will be necessary
  on platforms which have edge-triggered IRQs, as we need to call
  s3c24xx_serial_tx_chars to kick off transmission from outside IRQ
  context, with the port lock held.

* Rename s3c24xx_serial_rx_chars to s3c24xx_serial_rx_irq for
  consistency with the above. All it does now is call two other
  functions anyway.

Signed-off-by: default avatarHector Martin <marcan@marcan.st>
Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Tested-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210304213902.83903-22-marcan@marcan.st


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aaf14405

drivers/tty/serial/samsung_tty.c

+20 −14
Original line number Diff line number Diff line
@@ -827,7 +827,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id) 
	return IRQ_HANDLED;

}



static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id)

static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)

{

	struct s3c24xx_uart_port *ourport = dev_id;
@@ -836,16 +836,12 @@ static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id) 
	return s3c24xx_serial_rx_chars_pio(dev_id);

}



static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)

static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)

{

	struct s3c24xx_uart_port *ourport = id;

	struct uart_port *port = &ourport->port;

	struct circ_buf *xmit = &port->state->xmit;

	unsigned long flags;

	int count, dma_count = 0;



	spin_lock_irqsave(&port->lock, flags);



	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);



	if (ourport->dma && ourport->dma->tx_chan &&
@@ -862,7 +858,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) 
		wr_reg(port, S3C2410_UTXH, port->x_char);

		port->icount.tx++;

		port->x_char = 0;

		goto out;

		return;

	}



	/* if there isn't anything more to transmit, or the uart is now
@@ -871,7 +867,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) 


	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {

		s3c24xx_serial_stop_tx(port);

		goto out;

		return;

	}



	/* try and drain the buffer... */
@@ -893,7 +889,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) 


	if (!count && dma_count) {

		s3c24xx_serial_start_tx_dma(ourport, dma_count);

		goto out;

		return;

	}



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
@@ -904,8 +900,18 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) 


	if (uart_circ_empty(xmit))

		s3c24xx_serial_stop_tx(port);

}



static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)

{

	struct s3c24xx_uart_port *ourport = id;

	struct uart_port *port = &ourport->port;

	unsigned long flags;



	spin_lock_irqsave(&port->lock, flags);



	s3c24xx_serial_tx_chars(ourport);



out:

	spin_unlock_irqrestore(&port->lock, flags);

	return IRQ_HANDLED;

}
@@ -919,11 +925,11 @@ static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id) 
	irqreturn_t ret = IRQ_HANDLED;



	if (pend & S3C64XX_UINTM_RXD_MSK) {

		ret = s3c24xx_serial_rx_chars(irq, id);

		ret = s3c24xx_serial_rx_irq(irq, id);

		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);

	}

	if (pend & S3C64XX_UINTM_TXD_MSK) {

		ret = s3c24xx_serial_tx_chars(irq, id);

		ret = s3c24xx_serial_tx_irq(irq, id);

		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);

	}

	return ret;
@@ -1155,7 +1161,7 @@ static int s3c24xx_serial_startup(struct uart_port *port) 


	ourport->rx_enabled = 1;



	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,

	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,

			  s3c24xx_serial_portname(port), ourport);



	if (ret != 0) {
@@ -1169,7 +1175,7 @@ static int s3c24xx_serial_startup(struct uart_port *port) 


	ourport->tx_enabled = 1;



	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,

	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,

			  s3c24xx_serial_portname(port), ourport);



	if (ret) {