On Nov 06 2017 or thereabouts, Sébastien Szymanski wrote:
> 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 <sebastien.szyman...@armadeus.com>
> >> ---
> >> 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.
True.
So, commit 8e9faa15469e basically makes all transfert return -EIO and
should be reverted, right?
IMO, your commit should be:
if (ret != CP2112_GPIO_CONFIG_LENGTH) {
hid_err(hdev, "error setting GPIO config: %d\n", ret);
if (ret >= 0)
ret = -EIO;
goto exit;
}
ret = 0;
exit:
mutex_unlock(&dev->lock);
return ret;
How does that sound?
Cheers,
Benjamin
>
> 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
