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authorSonic Zhang <sonic.zhang@analog.com>2007-11-21 17:00:32 +0800
committerBryan Wu <cooloney@kernel.org>2007-11-21 17:00:32 +0800
commit759eb040901af60d8a1a2b59b93805521b156cbb (patch)
tree91a18e28643ff6112a7a4f7ee4468487c6b664a7 /drivers/serial
parentc051489df8b027238ff22d64d4e01ede3ad77dd5 (diff)
downloadop-kernel-dev-759eb040901af60d8a1a2b59b93805521b156cbb.zip
op-kernel-dev-759eb040901af60d8a1a2b59b93805521b156cbb.tar.gz
Blackfin Serial driver: Fix bug - serial driver in PIO mode cant handle input very quickly
Output as many bytes as possible in PIO tx handler. This reduce the number of tx interrupts and shorten the delay to handle rx interrupt. So, rx overrun disappears. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/bfin_5xx.c62
1 files changed, 14 insertions, 48 deletions
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index ac2a3ef..e059475 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -74,7 +74,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
#else
static void bfin_serial_do_work(struct work_struct *work);
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
-static void local_put_char(struct bfin_serial_port *uart, char ch);
#endif
static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
@@ -85,6 +84,9 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
static void bfin_serial_stop_tx(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+#ifndef CONFIG_BF54x
+ unsigned short ier;
+#endif
while (!(UART_GET_LSR(uart) & TEMT))
continue;
@@ -100,8 +102,6 @@ static void bfin_serial_stop_tx(struct uart_port *port)
UART_PUT_LSR(uart, TFI);
UART_CLEAR_IER(uart, ETBEI);
#else
- unsigned short ier;
-
ier = UART_GET_IER(uart);
ier &= ~ETBEI;
UART_PUT_IER(uart, ier);
@@ -210,23 +210,6 @@ int kgdb_get_debug_char(void)
#endif
#ifdef CONFIG_SERIAL_BFIN_PIO
-static void local_put_char(struct bfin_serial_port *uart, char ch)
-{
- unsigned short status;
- int flags = 0;
-
- spin_lock_irqsave(&uart->port.lock, flags);
-
- do {
- status = UART_GET_LSR(uart);
- } while (!(status & THRE));
-
- UART_PUT_CHAR(uart, ch);
- SSYNC();
-
- spin_unlock_irqrestore(&uart->port.lock, flags);
-}
-
static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
{
struct tty_struct *tty = uart->port.info->tty;
@@ -236,8 +219,8 @@ static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
struct pt_regs *regs = get_irq_regs();
#endif
- status = UART_GET_LSR(uart);
ch = UART_GET_CHAR(uart);
+ status = UART_GET_LSR(uart);
uart->port.icount.rx++;
#ifdef CONFIG_KGDB_UART
@@ -337,9 +320,12 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
return;
}
- local_put_char(uart, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- uart->port.icount.tx++;
+ 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);
+ uart->port.icount.tx++;
+ SSYNC();
+ }
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uart->port);
@@ -352,21 +338,11 @@ static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
-#ifdef CONFIG_BF54x
- unsigned short status;
spin_lock(&uart->port.lock);
- status = UART_GET_LSR(uart);
- while ((UART_GET_IER(uart) & ERBFI) && (status & DR)) {
+ while ((UART_GET_IER(uart) & ERBFI) && (UART_GET_LSR(uart) & DR))
bfin_serial_rx_chars(uart);
- status = UART_GET_LSR(uart);
- }
spin_unlock(&uart->port.lock);
-#else
- spin_lock(&uart->port.lock);
- while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_RX_READY)
- bfin_serial_rx_chars(uart);
- spin_unlock(&uart->port.lock);
-#endif
+
return IRQ_HANDLED;
}
@@ -374,21 +350,11 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
-#ifdef CONFIG_BF54x
- unsigned short status;
spin_lock(&uart->port.lock);
- status = UART_GET_LSR(uart);
- while ((UART_GET_IER(uart) & ETBEI) && (status & THRE)) {
+ if ((UART_GET_IER(uart) & ETBEI) && (UART_GET_LSR(uart) & THRE))
bfin_serial_tx_chars(uart);
- status = UART_GET_LSR(uart);
- }
spin_unlock(&uart->port.lock);
-#else
- spin_lock(&uart->port.lock);
- while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_TX_READY)
- bfin_serial_tx_chars(uart);
- spin_unlock(&uart->port.lock);
-#endif
+
return IRQ_HANDLED;
}
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