From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Archit Anant <architanant5@gmail.com>
Cc: jic23@kernel.org, dlechner@baylibre.com, lars@metafoo.de,
Michael.Hennerich@analog.com, nuno.sa@analog.com,
andy@kernel.org, linux-iio@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/4] iio: adc: ad799x: cache regulator voltage during probe
Date: Sun, 8 Mar 2026 23:12:48 +0200 [thread overview]
Message-ID: <aa3mUMKPaVY_t3G4@ashevche-desk.local> (raw)
In-Reply-To: <20260308182811.33471-3-architanant5@gmail.com>
On Sun, Mar 08, 2026 at 11:58:09PM +0530, Archit Anant wrote:
> Reading the regulator voltage via regulator_get_voltage() can be a slow
> operation. Since the reference voltage for this ADC is not expected to
> change at runtime, it is inefficient to query the regulator API every
> time userspace reads the IIO_CHAN_INFO_SCALE attribute.
>
> Determine the active reference voltage (either VREF or VCC) during
> probe() and cache it in a single variable in the state structure.
> This improves the performance of ad799x_read_raw(), removes the
> dependency on the regulator pointers during fast-path reads, and
> allows the removal of a redundant negative-value check.
...
> + *val = st->vref_uV / 1000;
Perhaps "(MICRO / MILLI)" instead of "1000" until we have a dedicate constant?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-03-08 21:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-08 18:28 [PATCH v4 0/4] iio: adc: ad799x: modernize resource management Archit Anant
2026-03-08 18:28 ` [PATCH v4 1/4] iio: adc: ad799x: make rx_buf static Archit Anant
2026-03-08 21:10 ` Andy Shevchenko
2026-03-08 18:28 ` [PATCH v4 2/4] iio: adc: ad799x: cache regulator voltage during probe Archit Anant
2026-03-08 21:12 ` Andy Shevchenko [this message]
2026-03-09 19:38 ` Jonathan Cameron
2026-03-08 18:28 ` [PATCH v4 3/4] iio: adc: ad799x: use devm_add_action_or_reset for regulators Archit Anant
2026-03-08 21:15 ` Andy Shevchenko
2026-03-08 18:28 ` [PATCH v4 4/4] iio: adc: ad799x: use devm_iio_device_register and drop remove Archit Anant
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