linux-kernel - Re: [PATCH] iio: remove unnecessary condition judgment in am2315_trigger

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Date:   Sat, 8 Sep 2018 15:17:51 +0100
From:   Jonathan Cameron <jic23@...nel.org>
To:     Himanshu Jha <himanshujha199640@...il.com>
Cc:     zhong jiang <zhongjiang@...wei.com>, knaack.h@....de,
        lars@...afoo.de, pmeerw@...erw.net, linux-iio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] iio: remove unnecessary condition judgment in
 am2315_trigger_handler

On Sat, 8 Sep 2018 17:59:13 +0530
Himanshu Jha <himanshujha199640@...il.com> wrote:

> On Sat, Sep 08, 2018 at 06:57:36PM +0800, zhong jiang wrote:
> > The iterator in for_each_set_bit is never null, therefore, remove
> > the redundant conditional judgment.
> > 
> > Signed-off-by: zhong jiang <zhongjiang@...wei.com>
> > ---
> >  drivers/iio/humidity/am2315.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
> > index 7d8669d..dc12e37 100644
> > --- a/drivers/iio/humidity/am2315.c
> > +++ b/drivers/iio/humidity/am2315.c
> > @@ -176,8 +176,7 @@ static irqreturn_t am2315_trigger_handler(int irq, void *p)
> >  		i = 0;
> >  		for_each_set_bit(bit, indio_dev->active_scan_mask,
> >  				 indio_dev->masklength) {
> > -			data->buffer[i] = (bit ? sensor_data.temp_data :
> > -						 sensor_data.hum_data);
> > +			data->buffer[i] = sensor_data.temp_data;  
> 
> No, this seems wrong!
> 
> We have buffer support to either take both readings(temp & humid)
> simultaneously, or only single channel using specified scan mask.

Key think is that bit most definitely can be 0 if the 0th bit is set.
This isn't a null check at all.

I'm curious, was this a by inspection case or did some script throw
this one up?

Thanks,

Jonathan

> 
> Patch title should be:
> 
> "iio: humidity: am2315: .... .. "
> 
> 
> Thanks