From: Shubhrajyoti Datta Date: Fri, 24 May 2019 09:11:28 +0000 (+0530) Subject: serial: uartps: Move the spinlock after the read of the tx empty X-Git-Tag: android-x86-9.0-r1~1^2~33^2~2 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=77bad0ab1b725e6c348277fcdb8790908286ca20;p=android-x86%2Fkernel.git 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 --- 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);