Groups > linux.kernel > #1520287

Re: [PATCH v3 16/28] staging: iio: tsl2583: updated code comment to match what the code does

From	Jonathan Cameron <jic23@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 16/28] staging: iio: tsl2583: updated code comment to match what the code does
Date	2016-11-12 18:20 +0100
Message-ID	<sCK8a-4X1-31@gated-at.bofh.it> (permalink)
References	<sBTQe-3Ic-3@gated-at.bofh.it> <sBTZU-3Mb-7@gated-at.bofh.it> <sCJvs-4tA-15@gated-at.bofh.it> <sCJOP-4AL-41@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 12/11/16 16:59, Brian Masney wrote:
> On Sat, Nov 12, 2016 at 04:36:37PM +0000, Jonathan Cameron wrote:
>> On 10/11/16 09:25, Brian Masney wrote:
>>> If channel 0 does not have any data, then the code sets the lux to zero.
>>> The corresponding comment says that the last value is returned. This
>>> updates the comment to correctly reflect what the code does.
>>>
>>> Signed-off-by: Brian Masney <masneyb@onstation.org>
>> Better perhaps to just return an error, -EAGAIN perhaps?
>> I'm not sure why it would not give a value.
> 
> This check is to avoid a division by zero. Here is the relevant code
> that wasn't shown in the diff:
> 
> 	if (!ch0) {
> 		/* have no data, so return 0 */
> 		ret = 0;
> 		chip->als_cur_info.lux = 0;
> 		goto done;
> 	}
> 
> 	/* calculate ratio */
> 	ratio = (ch1 << 15) / ch0;
> 
> Channel 0 is sensitive to both infrared and visible light. In total
> darkness, the sensor should return 0. Correct me if I am wrong, but
> I believe that returning 0 here is more correct than -EAGAIN.
> 
> Brian
> 
Fair enough I hadn't understood that.  Maybe expand the comment
to cover that?

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v3 16/28] staging: iio: tsl2583: updated code comment to match what the code does Brian Masney <masneyb@onstation.org> - 2016-11-10 10:40 +0100
  Re: [PATCH v3 16/28] staging: iio: tsl2583: updated code comment to  match what the code does Jonathan Cameron <jic23@kernel.org> - 2016-11-12 17:40 +0100
    Re: [PATCH v3 16/28] staging: iio: tsl2583: updated code comment to  match what the code does Brian Masney <masneyb@onstation.org> - 2016-11-12 18:00 +0100
      Re: [PATCH v3 16/28] staging: iio: tsl2583: updated code comment to  match what the code does Jonathan Cameron <jic23@kernel.org> - 2016-11-12 18:20 +0100

csiph-web