linux-kernel - [PATCH] HID: cp2112: prevent sleeping function called from invalid context

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Message-Id: <20190812160444.10402-1-benjamin.tissoires@redhat.com>
Date:   Mon, 12 Aug 2019 18:04:44 +0200
From:   Benjamin Tissoires <benjamin.tissoires@...hat.com>
To:     David Barksdale <dbarksdale@...ogix.com>,
        Jiri Kosina <jikos@...nel.org>
Cc:     linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>
Subject: [PATCH] HID: cp2112: prevent sleeping function called from invalid context

When calling request_threaded_irq() with a CP2112, the function
cp2112_gpio_irq_startup() is called in a IRQ context.

Therefore we can not sleep, and we can not call
cp2112_gpio_direction_input() there.

Move the call to cp2112_gpio_direction_input() earlier to have a working
driver.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
---
 drivers/hid/hid-cp2112.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 2310c96ccf4a..db1b55df0d13 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -1153,8 +1153,6 @@ static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
 
 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
 
-	cp2112_gpio_direction_input(gc, d->hwirq);
-
 	if (!dev->gpio_poll) {
 		dev->gpio_poll = true;
 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
@@ -1204,6 +1202,12 @@ static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
 		return PTR_ERR(dev->desc[pin]);
 	}
 
+	ret = cp2112_gpio_direction_input(&dev->gc, pin);
+	if (ret < 0) {
+		dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
+		goto err_desc;
+	}
+
 	ret = gpiochip_lock_as_irq(&dev->gc, pin);
 	if (ret) {
 		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
-- 
2.19.2