Paul Geurts 0d0dd383ac NFC: trf7970a: Ignore antenna noise when checking for RF field
[ Upstream commit a9bc28aa4e ]

The main channel Received Signal Strength Indicator (RSSI) measurement
is used to determine whether an RF field is present or not. RSSI != 0
is interpreted as an RF Field is present. This does not take RF noise
and measurement inaccuracy into account, and results in false positives
in the field.

Define a noise level and make sure the RF field is only interpreted as
present when the RSSI is above the noise level.

Fixes: 851ee3cbf8 ("NFC: trf7970a: Don't turn on RF if there is already an RF field")
Signed-off-by: Paul Geurts <paul.geurts@prodrive-technologies.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Link: https://patch.msgid.link/20260422100930.581237-1-paul.geurts@prodrive-technologies.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-23 13:03:28 +02:00
2026-05-23 13:03:09 +02:00
…
…
…
…
…
…
2026-05-23 13:03:09 +02:00
2026-05-17 17:13:54 +02:00
…

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%