[PATCH] net: rfkill: gpio: set GPIO direction

From: Rouven Czerwinski
Date: Wed Dec 06 2023 - 08:13:56 EST


Fix the undefined usage of the GPIO consumer API after retrieving the
GPIO description with GPIO_ASIS. The API documentation mentions that
GPIO_ASIS won't set a GPIO direction and requires the user to set a
direction before using the GPIO.

This can be confirmed on i.MX6 hardware, where rfkill-gpio is no longer
able to enabled/disable a device, presumably because the GPIO controller
was never configured for the output direction.

Fixes: b2f750c3a80b ("net: rfkill: gpio: prevent value glitch during probe")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
---
net/rfkill/rfkill-gpio.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c
index 5a81505fba9ac..3d9ae696397cf 100644
--- a/net/rfkill/rfkill-gpio.c
+++ b/net/rfkill/rfkill-gpio.c
@@ -126,6 +126,16 @@ static int rfkill_gpio_probe(struct platform_device *pdev)
return -EINVAL;
}

+ if (rfkill->reset_gpio)
+ ret = gpiod_direction_output(rfkill->reset_gpio, true);
+ if (ret)
+ return ret;
+
+ if (rfkill->shutdown_gpio)
+ ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
+ if (ret)
+ return ret;
+
rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
rfkill->type, &rfkill_gpio_ops,
rfkill);

base-commit: 994d5c58e50e91bb02c7be4a91d5186292a895c8
--
2.39.2