serial: bfin_uart: narrow the reboot condition in DMA tx interrupt

Check if xmit buffer pointers are set to zero.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sonic Zhang 2012-05-16 14:22:24 +08:00 committed by Greg Kroah-Hartman
parent b06d2f20cd
commit 239c25b1a0

View File

@ -532,7 +532,7 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
*/
UART_CLEAR_IER(uart, ETBEI);
uart->port.icount.tx += uart->tx_count;
if (!uart_circ_empty(xmit)) {
if (!(xmit->tail == 0 && xmit->head == 0)) {
xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)