Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 15 Jan 2024 11:13:45 +0200 | Subject | Re: [PATCH 2/3] iio: test: test gain-time-scale helpers | From | Matti Vaittinen <> |
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On 1/13/24 18:12, Jonathan Cameron wrote: > On Wed, 10 Jan 2024 12:12:55 +0200 > Matti Vaittinen <mazziesaccount@gmail.com> wrote: > >> Some light sensors can adjust both the HW-gain and integration time. >> There are cases where adjusting the integration time has similar impact >> to the scale of the reported values as gain setting has. >> >> IIO users do typically expect to handle scale by a single writable 'scale' >> entry. Driver should then adjust the gain/time accordingly. >> >> It however is difficult for a driver to know whether it should change >> gain or integration time to meet the requested scale. Usually it is >> preferred to have longer integration time which usually improves >> accuracy, but there may be use-cases where long measurement times can be >> an issue. Thus it can be preferable to allow also changing the >> integration time - but mitigate the scale impact by also changing the gain >> underneath. Eg, if integration time change doubles the measured values, >> the driver can reduce the HW-gain to half. >> >> The theory of the computations of gain-time-scale is simple. However, >> some people (undersigned) got that implemented wrong for more than once. >> Hence some gain-time-scale helpers were introduced. >> >> Add some simple tests to verify the most hairy functions. >> >> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> >> > Hi Matti, > > All seems reasonable to me. Some trivial formatting things inline > + I'm not planning to check the maths as you are the expert in all of > this so I'll just trust you!
Well, all checking is always welcome. Still, I kind of understand that you won't verify everything you see... Oh, and thanks for the trust. :)
> Also if this fails you get to pick up the pieces :)
This sure helps to trust ;)
As for things you commented - Thanks! I'll fix them and respin.
Yours, -- Matti
-- Matti Vaittinen Linux kernel developer at ROHM Semiconductors Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
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