Commit 07b5e16e authored by Anson Huang's avatar Anson Huang Committed by Greg Kroah-Hartman
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tty: serial: imx: add lock for registers save/restore 



In noirq suspend/resume stage with no_console_suspend enabled,
imx_uart_console_write() may be called to print out log_buf
message by printk(), so there will be race condition between
imx_uart_console_write() and imx_uart_save/restore_context(),
need to add lock to protect the registers save/restore operations.

Signed-off-by: default avatarAnson Huang <Anson.Huang@nxp.com>
Acked-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c974991d

drivers/tty/serial/imx.c

+11 −1
Original line number Diff line number Diff line
@@ -2371,8 +2371,13 @@ static int imx_uart_remove(struct platform_device *pdev) 


static void imx_uart_restore_context(struct imx_port *sport)

{

	if (!sport->context_saved)

	unsigned long flags;



	spin_lock_irqsave(&sport->port.lock, flags);

	if (!sport->context_saved) {

		spin_unlock_irqrestore(&sport->port.lock, flags);

		return;

	}



	imx_uart_writel(sport, sport->saved_reg[4], UFCR);

	imx_uart_writel(sport, sport->saved_reg[5], UESC);
@@ -2385,11 +2390,15 @@ static void imx_uart_restore_context(struct imx_port *sport) 
	imx_uart_writel(sport, sport->saved_reg[2], UCR3);

	imx_uart_writel(sport, sport->saved_reg[3], UCR4);

	sport->context_saved = false;

	spin_unlock_irqrestore(&sport->port.lock, flags);

}



static void imx_uart_save_context(struct imx_port *sport)

{

	unsigned long flags;



	/* Save necessary regs */

	spin_lock_irqsave(&sport->port.lock, flags);

	sport->saved_reg[0] = imx_uart_readl(sport, UCR1);

	sport->saved_reg[1] = imx_uart_readl(sport, UCR2);

	sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
@@ -2401,6 +2410,7 @@ static void imx_uart_save_context(struct imx_port *sport) 
	sport->saved_reg[8] = imx_uart_readl(sport, UBMR);

	sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);

	sport->context_saved = true;

	spin_unlock_irqrestore(&sport->port.lock, flags);

}



static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)

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