get_frontend() can't be called too early, as the device may not have it
yet. Yet, get_frontend() on OFDM standards can happen before FE_HAS_LOCK,
as the TMCC carriers (ISDB-T) or the TPS carriers (DVB-T) require a very
low signal to noise relation to be detected. The other carriers use
different modulations, so they require a higher SNR.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---
Documentation/DocBook/media/dvb/frontend.xml | 59 +++++++++++++++++++++-----
include/linux/dvb/frontend.h | 33 ++++++++++----
2 files changed, 72 insertions(+), 20 deletions(-)
diff --git a/Documentation/DocBook/media/dvb/frontend.xml b/Documentation/DocBook/media/dvb/frontend.xml
index aeaed59..5426bdc 100644
--- a/Documentation/DocBook/media/dvb/frontend.xml
+++ b/Documentation/DocBook/media/dvb/frontend.xml
@@ -207,18 +207,55 @@ spec.</para>
<para>Several functions of the frontend device use the fe_status data type defined
by</para>
<programlisting>
- typedef enum fe_status {
- FE_HAS_SIGNAL = 0x01, /⋆ found something above the noise level ⋆/
- FE_HAS_CARRIER = 0x02, /⋆ found a DVB signal ⋆/
- FE_HAS_VITERBI = 0x04, /⋆ FEC is stable ⋆/
- FE_HAS_SYNC = 0x08, /⋆ found sync bytes ⋆/
- FE_HAS_LOCK = 0x10, /⋆ everything's working... ⋆/
- FE_TIMEDOUT = 0x20, /⋆ no lock within the last ~2 seconds ⋆/
- FE_REINIT = 0x40 /⋆ frontend was reinitialized, ⋆/
- } fe_status_t; /⋆ application is recommned to reset ⋆/
+typedef enum fe_status {
+ FE_HAS_SIGNAL = 0x01,
+ FE_HAS_CARRIER = 0x02,
+ FE_HAS_VITERBI = 0x04,
+ FE_HAS_SYNC = 0x08,
+ FE_HAS_LOCK = 0x10,
+ FE_TIMEDOUT = 0x20,
+ FE_REINIT = 0x40,
+ FE_HAS_PARAMETERS = 0x80,
+} fe_status_t;
</programlisting>
-<para>to indicate the current state and/or state changes of the frontend hardware.
-</para>
+<para>to indicate the current state and/or state changes of the frontend hardware:
+</para>
+
+<informaltable><tgroup cols="2"><tbody>
+<row>
+<entry align="char">FE_HAS_SIGNAL</entry>
+<entry align="char">The frontend has found something above the noise level</entry>
+</row><row>
+<entry align="char">FE_HAS_CARRIER</entry>
+<entry align="char">The frontend has found a DVB signal</entry>
+</row><row>
+<entry align="char">FE_HAS_VITERBI</entry>
+<entry align="char">The frontend FEC code is stable</entry>
+</row><row>
+<entry align="char">FE_HAS_SYNC</entry>
+<entry align="char">Syncronization bytes was found</entry>
+</row><row>
+<entry align="char">FE_HAS_LOCK</entry>
+<entry align="char">The DVB were locked and everything is working</entry>
+</row><row>
+<entry align="char">FE_TIMEDOUT</entry>
+<entry align="char">no lock within the last about 2 seconds</entry>
+</row><row>
+<entry align="char">FE_REINIT</entry>
+<entry align="char">The frontend was reinitialized, application is
+recommended to reset DiSEqC, tone and parameters</entry>
+</row><row>
+<entry align="char">FE_HAS_PARAMETERS</entry>
+<entry align="char"><link linkend="FE_GET_SET_PROPERTY">
+<constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant></link> or
+<link linkend="FE_GET_FRONTEND"><constant>FE_GET_FRONTEND</constant></link> can now be
+called to provide the detected network parameters.
+This should be risen for example when the DVB-T TPS/ISDB-T TMCC is locked.
+This status can be risen before FE_HAS_SYNC, as the SNR required for
+parameters detection is lower than the requirement for the other
+carriers on the OFDM delivery systems.
+</entry>
+</row></tbody></tgroup></informaltable>
</section>
diff --git a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h
index cb4428a..38fa9ef 100644
--- a/include/linux/dvb/frontend.h
+++ b/include/linux/dvb/frontend.h
@@ -121,16 +121,31 @@ typedef enum fe_sec_mini_cmd {
} fe_sec_mini_cmd_t;
+/**
+ * enum fe_status - enumerates the possible frontend status
+ * @FE_HAS_SIGNAL: found something above the noise level
+ * @FE_HAS_CARRIER: found a DVB signal
+ * @FE_HAS_VITERBI: FEC is stable
+ * @FE_HAS_SYNC: found sync bytes
+ * @FE_HAS_LOCK: everything's working
+ * @FE_TIMEDOUT: no lock within the last ~2 seconds
+ * @FE_REINIT: frontend was reinitialized, application is recommended
+ * to reset DiSEqC, tone and parameters
+ * @FE_HAS_PARAMETERS: get_frontend() can now be called to provide the
+ * detected network parameters. This should be risen
+ * for example when the DVB-T TPS/ISDB-T TMCC is locked.
+ */
+
typedef enum fe_status {
- FE_HAS_SIGNAL = 0x01, /* found something above the noise level */
- FE_HAS_CARRIER = 0x02, /* found a DVB signal */
- FE_HAS_VITERBI = 0x04, /* FEC is stable */
- FE_HAS_SYNC = 0x08, /* found sync bytes */
- FE_HAS_LOCK = 0x10, /* everything's working... */
- FE_TIMEDOUT = 0x20, /* no lock within the last ~2 seconds */
- FE_REINIT = 0x40 /* frontend was reinitialized, */
-} fe_status_t; /* application is recommended to reset */
- /* DiSEqC, tone and parameters */
+ FE_HAS_SIGNAL = 0x01,
+ FE_HAS_CARRIER = 0x02,
+ FE_HAS_VITERBI = 0x04,
+ FE_HAS_SYNC = 0x08,
+ FE_HAS_LOCK = 0x10,
+ FE_TIMEDOUT = 0x20,
+ FE_REINIT = 0x40,
+ FE_HAS_PARAMETERS = 0x80,
+} fe_status_t;
typedef enum fe_spectral_inversion {
INVERSION_OFF,
--
1.7.8
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