linux-kernel - Re: [PATCH v4 3/3] iio: humidity: hdc3020: add threshold events support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240216203516.GA3873@debian>
Date: Fri, 16 Feb 2024 21:35:16 +0100
From: Dimitri Fedrau <dima.fedrau@...il.com>
To: Javier Carrasco <javier.carrasco.cruz@...il.com>
Cc: Jonathan Cameron <jic23@...nel.org>,
	Lars-Peter Clausen <lars@...afoo.de>, Nuno Sa <nuno.sa@...log.com>,
	Li peiyu <579lpy@...il.com>, linux-iio@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 3/3] iio: humidity: hdc3020: add threshold events
 support

Am Thu, Feb 15, 2024 at 12:18:41AM +0100 schrieb Javier Carrasco:
> On 14.02.24 09:53, Dimitri Fedrau wrote:
> > Add threshold events support for temperature and relative humidity. To
> > enable them the higher and lower threshold registers must be programmed
> > and the higher threshold must be greater then or equal to the lower
> > threshold. Otherwise the event is disabled. Invalid hysteresis values
> > are ignored by the device. There is no further configuration possible.
> > 
> > Tested by setting thresholds/hysteresis and turning the heater on/off.
> > Used iio_event_monitor in tools/iio to catch events while constantly
> > displaying temperature and humidity values.
> > 
> > Signed-off-by: Dimitri Fedrau <dima.fedrau@...il.com>
> > ---
> 
> Hi Dimitri,
>
Hi Javier,

> now that the decimal part is used, the resolution loss is within the
> ranges mentioned in the datasheet.
> 
> For the records: the truncated values lead to alerts slightly lower than
> the target alerts. Therefore, measured values below the "comfort zone"
> defined by the user (but close to the low alert) will not trigger
> events. The other way around is "more secure" because the target comfort
> zone is guaranteed:
> 
> -------- High val -> event (as expected)
> 
> ******** Target High Alert
> 
> -------- Meas -> **event** (still in target comfort zone)
> 
> ######## Truncated High Alert
> 
> ...
> 
> ******** Target Low Alert
> 
> -------- Meas -> **no event** (out of target comfort zone)
> 
> ######## Truncated Low Alert
> 
> -------- Meas -> event (as expected)
> 
> But as I said, the resolution loss is in the valid range anyway:
> 
> Tested-by: Javier Carrasco <javier.carrasco.cruz@...il.com>
> 
> Thank you for adding this feature.
>
thanks for testing.

Best regards,
Dimitri Fedrau