From f30ac0ce34f32bb998ac87e37b251374de03e603 Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Thu, 19 Jun 2008 17:46:39 +0800 Subject: 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 Signed-off-by: Bryan Wu --- drivers/serial/bfin_5xx.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) (limited to 'drivers/serial/bfin_5xx.c') diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c index f20952c43cb8..fd9bb777df28 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 = -- cgit v1.2.3-59-g8ed1b