From 1569039db0062c47c97ca0bf0c86210d26b8f412 Mon Sep 17 00:00:00 2001 From: Hao Liang Date: Thu, 26 Mar 2015 17:13:24 +0800 Subject: bfin uart: it will hang when read current y count if not disable dma irq Add irq disable and enable in bfin_serial_rx_dma_timeout in case of system hang. This reverts part of commit 9642dbe73c8a ("serial: bfin-uart: avoid dead lock in rx irq handler in smp kernel"). Signed-off-by: Hao Liang Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/bfin_uart.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/tty/serial/bfin_uart.c b/drivers/tty/serial/bfin_uart.c index 43b3e2c..155781e 100644 --- a/drivers/tty/serial/bfin_uart.c +++ b/drivers/tty/serial/bfin_uart.c @@ -464,6 +464,7 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart) int x_pos, pos; unsigned long flags; + dma_disable_irq_nosync(uart->rx_dma_channel); spin_lock_irqsave(&uart->rx_lock, flags); /* 2D DMA RX buffer ring is used. Because curr_y_count and @@ -496,6 +497,7 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart) } spin_unlock_irqrestore(&uart->rx_lock, flags); + dma_enable_irq(uart->rx_dma_channel); mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES); } -- cgit v1.1