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serial: uartps: Move the spinlock after the read of the tx empty

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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>
This commit is contained in:
Shubhrajyoti Datta 2019-05-24 14:41:28 +05:30 committed by Greg Kroah-Hartman
parent 1f74dfa803
commit 107475685a
1 changed files with 1 additions and 2 deletions
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3
drivers/tty/serial/xilinx_uartps.c
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@ -686,8 +686,6 @@ static void cdns_uart_set_termios(struct uart_port *port,
unsigned long flags; unsigned long flags;
unsigned int ctrl_reg, mode_reg; unsigned int ctrl_reg, mode_reg;
spin_lock_irqsave(&port->lock, flags);
/* Wait for the transmit FIFO to empty before making changes */ /* Wait for the transmit FIFO to empty before making changes */
if (!(readl(port->membase + CDNS_UART_CR) & if (!(readl(port->membase + CDNS_UART_CR) &
CDNS_UART_CR_TX_DIS)) { CDNS_UART_CR_TX_DIS)) {
@ -696,6 +694,7 @@ static void cdns_uart_set_termios(struct uart_port *port,
cpu_relax(); cpu_relax();
} }
} }
spin_lock_irqsave(&port->lock, flags);
/* Disable the TX and RX to set baud rate */ /* Disable the TX and RX to set baud rate */
ctrl_reg = readl(port->membase + CDNS_UART_CR); ctrl_reg = readl(port->membase + CDNS_UART_CR);