From: Qipan Li <Qipan.Li@xxxxxxx> In special condition, when cpu schedule into rx_tmo_process_tl or rx_dma_complete_tl and all the receive dma tasks have done, it will go into endless loop because no dma task cookie status be changed. Signed-off-by: Qipan Li <Qipan.Li@xxxxxxx> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx> --- drivers/tty/serial/sirfsoc_uart.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c index 48cceaf..ffeb766 100644 --- a/drivers/tty/serial/sirfsoc_uart.c +++ b/drivers/tty/serial/sirfsoc_uart.c @@ -488,6 +488,7 @@ static void sirfsoc_rx_tmo_process_tl(unsigned long param) unsigned int count; struct dma_tx_state tx_state; unsigned long flags; + int i = 0; spin_lock_irqsave(&port->lock, flags); while (DMA_COMPLETE == dmaengine_tx_status(sirfport->rx_dma_chan, @@ -497,6 +498,9 @@ static void sirfsoc_rx_tmo_process_tl(unsigned long param) SIRFSOC_RX_DMA_BUF_SIZE); sirfport->rx_completed++; sirfport->rx_completed %= SIRFSOC_RX_LOOP_BUF_CNT; + i++; + if (i > SIRFSOC_RX_LOOP_BUF_CNT) + break; } count = CIRC_CNT(sirfport->rx_dma_items[sirfport->rx_issued].xmit.head, sirfport->rx_dma_items[sirfport->rx_issued].xmit.tail, @@ -713,6 +717,8 @@ static void sirfsoc_uart_rx_dma_complete_tl(unsigned long param) struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en; struct dma_tx_state tx_state; unsigned long flags; + int i = 0; + spin_lock_irqsave(&port->lock, flags); while (DMA_COMPLETE == dmaengine_tx_status(sirfport->rx_dma_chan, sirfport->rx_dma_items[sirfport->rx_completed].cookie, @@ -726,6 +732,9 @@ static void sirfsoc_uart_rx_dma_complete_tl(unsigned long param) else sirfport->rx_completed++; sirfport->rx_completed %= SIRFSOC_RX_LOOP_BUF_CNT; + i++; + if (i > SIRFSOC_RX_LOOP_BUF_CNT) + break; } spin_unlock_irqrestore(&port->lock, flags); tty_flip_buffer_push(&port->state->port); -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
