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authorSonic Zhang <sonic.zhang@analog.com>2008-06-19 17:46:39 +0800
committerBryan Wu <cooloney@kernel.org>2008-06-19 17:46:39 +0800
commitf30ac0ce34f32bb998ac87e37b251374de03e603 (patch)
treecb22bb5d8ec4ef450902552c66809188a5d788bf /drivers
parentec64b6c8763c83899908fdd62746435c19211686 (diff)
Blackfin Serial Driver: Use timer to poll CTS PIN instead of workqueue.
This allows other threads to run when the serial driver polls the CTS PIN in a loop. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/serial/bfin_5xx.c40
1 files changed, 18 insertions, 22 deletions
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index f20952c43cb..fd9bb777df2 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -49,6 +49,7 @@
#define DMA_RX_YCOUNT (PAGE_SIZE / DMA_RX_XCOUNT)
#define DMA_RX_FLUSH_JIFFIES (HZ / 50)
+#define CTS_CHECK_JIFFIES (HZ / 50)
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
@@ -290,11 +291,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.info->xmit;
- if (uart->port.x_char) {
- UART_PUT_CHAR(uart, uart->port.x_char);
- uart->port.icount.tx++;
- uart->port.x_char = 0;
- }
/*
* Check the modem control lines before
* transmitting anything.
@@ -306,6 +302,12 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
return;
}
+ if (uart->port.x_char) {
+ UART_PUT_CHAR(uart, uart->port.x_char);
+ uart->port.icount.tx++;
+ uart->port.x_char = 0;
+ }
+
while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -345,15 +347,6 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
}
#endif
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
-static void bfin_serial_do_work(struct work_struct *work)
-{
- struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
-
- bfin_serial_mctrl_check(uart);
-}
-#endif
-
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
{
@@ -361,6 +354,12 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
uart->tx_done = 0;
+ /*
+ * Check the modem control lines before
+ * transmitting anything.
+ */
+ bfin_serial_mctrl_check(uart);
+
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
uart->tx_count = 0;
uart->tx_done = 1;
@@ -373,12 +372,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
uart->port.x_char = 0;
}
- /*
- * Check the modem control lines before
- * transmitting anything.
- */
- bfin_serial_mctrl_check(uart);
-
uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
uart->tx_count = UART_XMIT_SIZE - xmit->tail;
@@ -565,7 +558,10 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
if (!(status & TIOCM_CTS)) {
tty->hw_stopped = 1;
- schedule_work(&uart->cts_workqueue);
+ uart->cts_timer.data = (unsigned long)(uart);
+ uart->cts_timer.function = (void *)bfin_serial_mctrl_check;
+ uart->cts_timer.expires = jiffies + CTS_CHECK_JIFFIES;
+ add_timer(&(uart->cts_timer));
} else {
tty->hw_stopped = 0;
}
@@ -885,7 +881,7 @@ static void __init bfin_serial_init_ports(void)
init_timer(&(bfin_serial_ports[i].rx_dma_timer));
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
+ init_timer(&(bfin_serial_ports[i].cts_timer));
bfin_serial_ports[i].cts_pin =
bfin_serial_resource[i].uart_cts_pin;
bfin_serial_ports[i].rts_pin =