serial: imx: Grab port lock in imx_uart_enable_wakeup()

esben · gregkh · commit 3c199ed5bd64 · 2024-10-11T08:13:35.000+02:00
The port lock needs to be held when doing read-modify-write on UCR1 and UCR3. Signed-off-by: Esben Haabendal <esben@geanix.com> Link: https://lore.kernel.org/r/20240913-serial-imx-lockfix-v1-1-4d102746c89d@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
@@ -2580,10 +2580,13 @@ static void imx_uart_save_context(struct imx_port *sport)
 	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
+/* called with irq off */
 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 {
 	u32 ucr3;
 
+	uart_port_lock(&sport->port);
+
 	ucr3 = imx_uart_readl(sport, UCR3);
 	if (on) {
 		imx_uart_writel(sport, USR1_AWAKE, USR1);
@@ -2603,6 +2606,8 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 		}
 		imx_uart_writel(sport, ucr1, UCR1);
 	}
+
+	uart_port_unlock(&sport->port);
 }
 
 static int imx_uart_suspend_noirq(struct device *dev)

Original file line number	Diff line number	Diff line change
`@@ -2580,10 +2580,13 @@ static void imx_uart_save_context(struct imx_port *sport)`
`2580`	`2580`	`uart_port_unlock_irqrestore(&sport->port, flags);`
`2581`	`2581`	`}`
`2582`	`2582`
	`2583`	`+/* called with irq off */`
`2583`	`2584`	`static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)`
`2584`	`2585`	`{`
`2585`	`2586`	`u32 ucr3;`
`2586`	`2587`
	`2588`	`+ uart_port_lock(&sport->port);`
	`2589`	`+`
`2587`	`2590`	`ucr3 = imx_uart_readl(sport, UCR3);`
`2588`	`2591`	`if (on) {`
`2589`	`2592`	`imx_uart_writel(sport, USR1_AWAKE, USR1);`
`@@ -2603,6 +2606,8 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)`
`2603`	`2606`	`}`
`2604`	`2607`	`imx_uart_writel(sport, ucr1, UCR1);`
`2605`	`2608`	`}`
	`2609`	`+`
	`2610`	`+ uart_port_unlock(&sport->port);`
`2606`	`2611`	`}`
`2607`	`2612`
`2608`	`2613`	`static int imx_uart_suspend_noirq(struct device *dev)`