Re: [PATCH] Input: adc-joystick - fix ordering in adc_joystick_probe()

From: Artur Rojek
Date: Mon Jul 18 2022 - 05:25:23 EST


On 2022-07-09 06:35, Dmitry Torokhov wrote:
We should register the IIO buffer before we register the input device,
because as soon as the device is registered input handlers may attach to
it, resulting in a call to adc_joystick_open() which makes use of the said
buffer.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---

Not tested on hardware...
Hi Dmitry,

nice catch, thanks! I will verify the operation on hardware some time over the weekend.
Small nitpick inline. With that changed:

Acked-by: Artur Rojek <contact@xxxxxxxxxxxxxx>


drivers/input/joystick/adc-joystick.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/input/joystick/adc-joystick.c
b/drivers/input/joystick/adc-joystick.c
index 78ebca7d400a..e0cfdc84763f 100644
--- a/drivers/input/joystick/adc-joystick.c
+++ b/drivers/input/joystick/adc-joystick.c
@@ -222,13 +222,6 @@ static int adc_joystick_probe(struct platform_device *pdev)
if (error)
return error;

- input_set_drvdata(input, joy);
- error = input_register_device(input);
- if (error) {
- dev_err(dev, "Unable to register input device\n");
- return error;
- }
-
joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
if (IS_ERR(joy->buffer)) {
dev_err(dev, "Unable to allocate callback buffer\n");
@@ -241,6 +234,14 @@ static int adc_joystick_probe(struct platform_device *pdev)
return error;
}

+ input_set_drvdata(input, joy);
+
+ error = input_register_device(input);
+ if (error) {
+ dev_err(dev, "Unable to register input device\n");
+ return error;
+ }
+
return 0;
Since this is now the last thing the function does, we can simplify the code a bit:
```
error = input_register_device(input);
if (error)
dev_err(dev, "Unable to register input device\n");

return error;
```

Cheers,
Artur
}

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