From 9b95c9d93dace8566865758e3c64d21a84a9d06c Mon Sep 17 00:00:00 2001 From: Shubhrajyoti Datta Date: Fri, 24 May 2019 14:41:28 +0530 Subject: [PATCH] serial: uartps: Move the spinlock after the read of the tx empty commit 107475685abfdee504bb0ef4824f15797f6d2d4d upstream. Currently we are doing a read of the status register. Move the spinlock after that as the reads need not be spinlock protected. This patch prevents relaxing the cpu with spinlock held. Signed-off-by: Shubhrajyoti Datta Cc: Pavel Machek Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/xilinx_uartps.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 9826a15bfd87..81657f09761c 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -690,8 +690,6 @@ static void cdns_uart_set_termios(struct uart_port *port, unsigned int ctrl_reg, mode_reg, val; int err; - spin_lock_irqsave(&port->lock, flags); - /* Wait for the transmit FIFO to empty before making changes */ if (!(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_TX_DIS)) { @@ -703,6 +701,7 @@ static void cdns_uart_set_termios(struct uart_port *port, return; } } + spin_lock_irqsave(&port->lock, flags); /* Disable the TX and RX to set baud rate */ ctrl_reg = readl(port->membase + CDNS_UART_CR);