Re: [PATCH 05/12] iio: dac: rohm-bd79703: Do not allow writing SCALE
From: Matti Vaittinen
Date: Mon Aug 17 2026 - 01:08:25 EST
On 17/08/2026 04:32, Jonathan Cameron wrote:
On Mon, 10 Aug 2026 10:51:38 +0300
Matti Vaittinen <matti.vaittinen@xxxxxxxxx> wrote:
From: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
The BD79703 has adds IIO_CHAN_INFO_SCALE in the info_mask_shared_by_type
so users can read the scale, which depends on the used reference
voltage. This, however, enables users to try writing the scale as well.
This isn't really supported but the bd79703_write_raw() does not check
the mask, and if written scale values pass the validation, the driver
will proceed writing the DAC value when users writes the scale.
Prevent the unsupported scale setting and return an error.
Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
Fixes: af6aca656a85 ("iio: dac: Support ROHM BD79703 DAC")
Applied.
BTW convention is Fixes goes before SoB.
I did wonder if is documented anywhere and claude sent me
to the tip docs.
https://www.kernel.org/doc/Documentation/process/maintainer-tip.rst
IIO can follow that.
Anyhow, I'll swap them around whilst applying.
Thanks x2. (Once for pointing it out and once for fixing it!)
Yours,
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~