From a1d9947031868a010d22c42ede61aaa8dee519e4 Mon Sep 17 00:00:00 2001 From: Shubhrajyoti Datta Date: Thu, 16 Apr 2020 17:56:08 +0800 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 Signed-off-by: Yang Yingliang --- 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 7cbee19ea93d..31950a38f0fb 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -686,8 +686,6 @@ 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)) { @@ -699,6 +697,7 @@ 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); -- GitLab