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From: Rouven Czerwinski <r.czerwinski@pengutronix.de>
To: Johannes Berg <johannes.berg@intel.com>,
	Josua Mayer <josua@solid-run.com>,
	linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: pza@pengutronix.de,
	Rouven Czerwinski <r.czerwinski@pengutronix.de>,
	stable@vger.kernel.org,
	Johannes Berg <johannes@sipsolutions.net>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>
Subject: [PATCH v2] net: rfkill: gpio: set GPIO direction
Date: Thu,  7 Dec 2023 08:58:36 +0100
Message-Id: <20231207075835.3091694-1-r.czerwinski@pengutronix.de>
In-Reply-To: <20231206131336.3099727-1-r.czerwinski@pengutronix.de>
References: <20231206131336.3099727-1-r.czerwinski@pengutronix.de>
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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@vger.kernel.org
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
---
v2:
- remove the if clauses, the gpiod_direction_* functions can handle NULL
  gpio descriptors.

 net/rfkill/rfkill-gpio.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c
index 5a81505fba9ac..4e32d659524e0 100644
--- a/net/rfkill/rfkill-gpio.c
+++ b/net/rfkill/rfkill-gpio.c
@@ -126,6 +126,14 @@ static int rfkill_gpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	ret = gpiod_direction_output(rfkill->reset_gpio, true);
+	if (ret)
+		return ret;
+
+	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