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+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/userspace-api/media/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _FE_READ_SNR:
+
+***********
+FE_READ_SNR
+***********
+
+Name
+====
+
+FE_READ_SNR
+
+.. attention:: This ioctl is deprecated.
+
+Synopsis
+========
+
+.. c:function:: int  ioctl(int fd, FE_READ_SNR, int16_t *snr)
+    :name: FE_READ_SNR
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :c:func:`open() <dvb-fe-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.