From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Christofer Jonason <christofer.jonason@guidelinegeo.com>
Cc: jic23@kernel.org, lars@metafoo.de, dlechner@baylibre.com,
nuno.sa@analog.com, andy@kernel.org, michal.simek@amd.com,
victor.jonsson@guidelinegeo.com, linux-iio@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] iio: adc: xilinx-xadc: Fix sequencer mode in postdisable for dual mux
Date: Wed, 4 Mar 2026 15:40:05 +0200 [thread overview]
Message-ID: <aag2NQTBysQYMU--@ashevche-desk.local> (raw)
In-Reply-To: <20260304090727.1800289-1-christofer.jonason@guidelinegeo.com>
On Wed, Mar 04, 2026 at 10:07:27AM +0100, Christofer Jonason wrote:
> xadc_postdisable() unconditionally sets the sequencer to continuous
> mode. For dual external multiplexer configurations this is incorrect:
> simultaneous sampling mode is required so that ADC-A samples through
> the mux on VAUX[0-7] while ADC-B simultaneously samples through the
> mux on VAUX[8-15]. In continuous mode only ADC-A is active, so
> VAUX[8-15] channels return incorrect data.
>
> Since postdisable is also called from xadc_probe() to set the initial
> idle state, the wrong sequencer mode is active from the moment the
> driver loads.
>
> The preenable path already uses xadc_get_seq_mode() which returns
> SIMULTANEOUS for dual mux. Fix postdisable to do the same.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-03-04 13:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-04 9:07 [PATCH v2] iio: adc: xilinx-xadc: Fix sequencer mode in postdisable for dual mux Christofer Jonason
2026-03-04 11:40 ` Nuno Sá
2026-03-04 13:40 ` Andy Shevchenko [this message]
2026-03-07 12:41 ` Jonathan Cameron
2026-03-10 7:42 ` Michal Simek
2026-03-25 8:04 ` Christofer Jonason
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