diff options
| author | Steven Miao <realmz6@gmail.com> | 2012-11-07 06:27:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-16 01:59:58 +0100 |
| commit | 9642dbe73c8a3b55a812253fcb9add9eeed4ca81 (patch) | |
| tree | bdd51cf2a84b33b7c672d738b5a1eaf12bab342d | |
| parent | serial: cast before shifting on port io (diff) | |
| download | linux-9642dbe73c8a3b55a812253fcb9add9eeed4ca81.tar.xz linux-9642dbe73c8a3b55a812253fcb9add9eeed4ca81.zip | |
serial: bfin-uart: avoid dead lock in rx irq handler in smp kernel
Disabing dma irq and lock bottom half in smp kernel doesn't ensure exclusive
uart access. Call spin_lock_irqsave() instead.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/bfin_uart.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/tty/serial/bfin_uart.c b/drivers/tty/serial/bfin_uart.c index 9242d56ba267..ca64c4a83ce0 100644 --- a/drivers/tty/serial/bfin_uart.c +++ b/drivers/tty/serial/bfin_uart.c @@ -477,9 +477,9 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart) 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_bh(&uart->rx_lock); + spin_lock_irqsave(&uart->rx_lock, flags); /* 2D DMA RX buffer ring is used. Because curr_y_count and * curr_x_count can't be read as an atomic operation, @@ -510,8 +510,7 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart) uart->rx_dma_buf.tail = uart->rx_dma_buf.head; } - spin_unlock_bh(&uart->rx_lock); - dma_enable_irq(uart->rx_dma_channel); + spin_unlock_irqrestore(&uart->rx_lock, flags); mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES); } |