diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index d57bf3e708d8..e99a28387505 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -96,6 +96,7 @@ /* PDC registers */ #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) +#define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR) #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR) #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR) @@ -562,17 +563,22 @@ static void atmel_tx_dma(struct uart_port *port) struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx; int count; + /* nothing left to transmit? */ + if (UART_GET_TCR(port)) + return; + xmit->tail += pdc->ofs; xmit->tail &= UART_XMIT_SIZE - 1; port->icount.tx += pdc->ofs; pdc->ofs = 0; - if (!uart_circ_empty(xmit)) { - /* more to transmit - setup next transfer */ + /* more to transmit - setup next transfer */ - /* disable PDC transmit */ - UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); + /* disable PDC transmit */ + UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); + + if (!uart_circ_empty(xmit)) { dma_sync_single_for_device(port->dev, pdc->dma_addr, pdc->dma_size, @@ -586,11 +592,6 @@ static void atmel_tx_dma(struct uart_port *port) /* re-enable PDC transmit and interrupts */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else { - /* nothing left to transmit - disable the transmitter */ - - /* disable PDC transmit */ - UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)