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path: root/drivers/tty/serial/amba-pl011.c
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Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
-rw-r--r--drivers/tty/serial/amba-pl011.c23
1 files changed, 14 insertions, 9 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 53af53c43e8c..e3756a9a9b53 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1302,14 +1302,15 @@ static void pl011_stop_tx(struct uart_port *port)
pl011_dma_tx_stop(uap);
}
-static void pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
/* Start TX with programmed I/O only (no DMA) */
static void pl011_start_tx_pio(struct uart_amba_port *uap)
{
- uap->im |= UART011_TXIM;
- pl011_write(uap->im, uap, REG_IMSC);
- pl011_tx_chars(uap, false);
+ if (pl011_tx_chars(uap, false)) {
+ uap->im |= UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ }
}
static void pl011_start_tx(struct uart_port *port)
@@ -1389,25 +1390,26 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
return true;
}
-static void pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
+/* Returns true if tx interrupts have to be (kept) enabled */
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
{
struct circ_buf *xmit = &uap->port.state->xmit;
int count = uap->fifosize >> 1;
if (uap->port.x_char) {
if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
- return;
+ return true;
uap->port.x_char = 0;
--count;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
pl011_stop_tx(&uap->port);
- return;
+ return false;
}
/* If we are using DMA mode, try to send some characters. */
if (pl011_dma_tx_irq(uap))
- return;
+ return true;
do {
if (likely(from_irq) && count-- == 0)
@@ -1422,8 +1424,11 @@ static void pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uap->port);
- if (uart_circ_empty(xmit))
+ if (uart_circ_empty(xmit)) {
pl011_stop_tx(&uap->port);
+ return false;
+ }
+ return true;
}
static void pl011_modem_status(struct uart_amba_port *uap)