From 53794183225f25830ab40e1c83ae885f11501784 Mon Sep 17 00:00:00 2001 From: Jiada Wang Date: Mon, 13 Apr 2015 18:31:43 +0900 Subject: [PATCH] serial: imx: protect Soft Reset of port with lock Previously Soft Reset (clear of SRST bit in UCR2 register) of UART in startup is not protected by lock, which may have race with console_write, as console_write may occur at anytime even when UART port is shutdown. To avoid this race, protect Soft reset of UART port with spin_lock. Signed-off-by: Jiada Wang Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index c8cfa0637128..38717c7bb46f 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1114,6 +1114,12 @@ static int imx_startup(struct uart_port *port) writel(temp & ~UCR4_DREN, sport->port.membase + UCR4); + /* Can we enable the DMA support? */ + if (is_imx6q_uart(sport) && !uart_console(port) && + !sport->dma_is_inited) + imx_uart_dma_init(sport); + + spin_lock_irqsave(&sport->port.lock, flags); /* Reset fifo's and state machines */ i = 100; @@ -1124,13 +1130,6 @@ static int imx_startup(struct uart_port *port) while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0)) udelay(1); - /* Can we enable the DMA support? */ - if (is_imx6q_uart(sport) && !uart_console(port) && - !sport->dma_is_inited) - imx_uart_dma_init(sport); - - spin_lock_irqsave(&sport->port.lock, flags); - /* * Finally, clear and enable interrupts */