From 107475685abfdee504bb0ef4824f15797f6d2d4d Mon Sep 17 00:00:00 2001
From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Date: Fri, 24 May 2019 14:41:28 +0530
Subject: [PATCH] serial: uartps: Move the spinlock after the read of the tx
empty
Git-commit: 107475685abfdee504bb0ef4824f15797f6d2d4d
Patch-mainline: v5.3-rc1
References: git-fixes
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 <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
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 605354fd60b1..33ac898fb36e 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 long flags;
unsigned int ctrl_reg, mode_reg;
- 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)) {
@@ -696,6 +694,7 @@ static void cdns_uart_set_termios(struct uart_port *port,
cpu_relax();
}
}
+ spin_lock_irqsave(&port->lock, flags);
/* Disable the TX and RX to set baud rate */
ctrl_reg = readl(port->membase + CDNS_UART_CR);
--
2.16.4