On 11/06/2017 09:11 AM, Benjamin Tissoires wrote:
> On Nov 02 2017 or thereabouts, Sébastien 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: Sébastien Szymanski <[email protected]>
>> ---
>> 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.
As explained in the interface specification, the device doesn't answer
to set reports, so the transfer should be CP2112_GPIO_CONFIG_LENGTH (5)
bytes.
>
>> 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?
Well, the commit I mentioned in the Fixes tag, changes from
- return ret <= 0 ? ret : -EIO;
to
+ return ret < 0 ? ret : -EIO;
because ret being 0 could mean that one of the hid_hw_raw_request
returned 0.
Regards,
>
> I'd rather keep the same exit path in both cases, error or success.
>
> Cheers,
> Benjamin
>
>
>>
>> exit:
>> mutex_unlock(&dev->lock);
>> --
>> 2.7.3
>>
--
Sébastien Szymanski
Software engineer, Armadeus Systems
Tel: +33 (0)9 72 29 41 44
Fax: +33 (0)9 72 28 79 26
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