This patch adds a check for the GPIOs property existence, before the
GPIO is requested. This fixes an issue seen when the 8250 mctrl_gpio
support is added (2nd patch in this patch series) on x86 platforms using
ACPI. Please find a details problem description here:

https://lkml.org/lkml/2016/8/9/357

Signed-off-by: Stefan Roese <[email protected]>
Cc: Mika Westerberg <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Yegor Yefremov <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Giulio Benetti <[email protected]>
---
 drivers/tty/serial/serial_mctrl_gpio.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/tty/serial/serial_mctrl_gpio.c 
b/drivers/tty/serial/serial_mctrl_gpio.c
index 39ed56214cd3..cac50b20a119 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -116,6 +116,13 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device 
*dev, unsigned int idx)
 
        for (i = 0; i < UART_GPIO_MAX; i++) {
                enum gpiod_flags flags;
+               char *gpio_str;
+
+               /* Check if GPIO property exists and continue if not */
+               gpio_str = kasprintf(GFP_KERNEL, "%s-gpios",
+                                    mctrl_gpios_desc[i].name);
+               if (!device_property_present(dev, gpio_str))
+                       continue;
 
                if (mctrl_gpios_desc[i].dir_out)
                        flags = GPIOD_OUT_LOW;
-- 
2.21.0

Reply via email to