Re: [PATCH 3/3] HID: cp2112: fix broken gpio_direction_input callback

From: Benjamin Tissoires
Date: Mon Nov 06 2017 - 03:11:33 EST


On Nov 02 2017 or thereabouts, SÃbastien Szymanski wrote:
> When everything goes smoothly, ret is set to 0 which makes the function
> to return EIO error.
>
> Fixes: 8e9faa15469e ("HID: cp2112: fix gpio-callback error handling")
> Signed-off-by: SÃbastien Szymanski <sebastien.szymanski@xxxxxxxxxxxx>
> ---
> drivers/hid/hid-cp2112.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
> index 28e3c18..f7754a6 100644
> --- a/drivers/hid/hid-cp2112.c
> +++ b/drivers/hid/hid-cp2112.c
> @@ -205,12 +205,13 @@ static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
> CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
> HID_REQ_SET_REPORT);
> - if (ret < 0) {
> + if (ret != CP2112_GPIO_CONFIG_LENGTH) {

Ack for this.

> hid_err(hdev, "error setting GPIO config: %d\n", ret);
> goto exit;
> }
>
> - ret = 0;
> + mutex_unlock(&dev->lock);
> + return 0;

Wouldn't it be better to just turn
- return ret < 0 ? ret : -EIO;
into
+ return ret <= 0 ? ret : -EIO;
at the end of the function?

I'd rather keep the same exit path in both cases, error or success.

Cheers,
Benjamin


>
> exit:
> mutex_unlock(&dev->lock);
> --
> 2.7.3
>