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: Hector Martin <marcan@marcan.st>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Tested-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210304213902.83903-22-marcan@marcan.st
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hector Martin 2021-03-05 06:38:56 +09:00 committed by Greg Kroah-Hartman
parent aaf144059b
commit ad5613b98a

View file

@ -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) {