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| author |   Anson Huang <Anson.Huang@nxp.com> | 2018-09-05 09:24:26 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-18 16:07:24 +0200 |
| commit | 07b5e16e9830878291bc83df70e87cdb0833517c (patch) | |
| tree | 58ad1807ac2c3ff5dbfbdb006e8ab9f5995decfc /drivers/tty/serial | |
| parent | tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr (diff) | |
| download | linux-dev-07b5e16e9830878291bc83df70e87cdb0833517c.tar.xz linux-dev-07b5e16e9830878291bc83df70e87cdb0833517c.zip | |
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: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/imx.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 3069ee93583e..2634272ad0fb 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -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) |