From 5b3fc3f74a428259ded6d0b228baee43921b4de6 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 c8cfa06371280..38717c7bb46f3 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 */ -- 2.39.5