Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/dvb/fe-read-snr.rst b/Documentation/userspace-api/media/dvb/fe-read-snr.rst
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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: DTV.fe
+
+.. _FE_READ_SNR:
+
+***********
+FE_READ_SNR
+***********
+
+Name
+====
+
+FE_READ_SNR
+
+.. attention:: This ioctl is deprecated.
+
+Synopsis
+========
+
+.. c:macro:: FE_READ_SNR
+
+``int ioctl(int fd, FE_READ_SNR, int16_t *snr)``
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :c:func:`open()`.
+
+``snr``
+    The signal-to-noise ratio is stored into \*snr.
+
+Description
+===========
+
+This ioctl call returns the signal-to-noise ratio for the signal
+currently received by the front-end. For this command, read-only access
+to the device is sufficient.
+
+Return Value
+============
+
+On success 0 is returned.
+
+On error -1 is returned, and the ``errno`` variable is set
+appropriately.
+
+Generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.