diff options
| author | Harald Welte <laforge@gnumonks.org> | 2017-03-24 10:41:04 +0100 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2017-04-06 18:41:01 +0200 |
| commit | bbe90fd6511c9a0abdb5f41d13c5ab0135b903f7 (patch) | |
| tree | 70b1f03f31d9b84b1b1bf5f00787bc7cf2cadc6b /src/common/tx_power.c | |
| parent | e16b59357411ffa4903ac110ac4ce46d343e878d (diff) | |
sysmobts: Don't start with 0dBm TRX output power before ramping
In case a system has a high-gain external PA (like a 40dB PA) connected
externally, we cannot simply switch the transceiver to 0 dBm in
trx_init() only to then start the ramping at much lower levels once the
PHJ completes in trx_init_compl_cb(). The result would be a short
0 + 40 dBm spike followed by later ramping. We want to avoid that
spike, particularly its associated inrush current, so let's bring up the
board with smething very conservative like -50 dBm, and then ramp from
there.
Change-Id: I0ad91fce64f65e0213c9fcfde3390ace519055db
Fixes: SYS#3259
Diffstat (limited to 'src/common/tx_power.c')
| -rw-r--r-- | src/common/tx_power.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/common/tx_power.c b/src/common/tx_power.c index c5179181..3dfe1f7e 100644 --- a/src/common/tx_power.c +++ b/src/common/tx_power.c @@ -289,3 +289,18 @@ int power_ramp_start(struct gsm_bts_trx *trx, int p_total_tgt_mdBm, int bypass) return 0; } + +/* determine the initial transceiver output power at start-up time */ +int power_ramp_initial_power_mdBm(struct gsm_bts_trx *trx) +{ + struct trx_power_params *tpp = &trx->power_params; + int pout_mdBm; + + /* this is the maximum initial output on the antenna connector + * towards the antenna */ + pout_mdBm = tpp->ramp.max_initial_pout_mdBm; + + /* use this as input to compute transceiver board power + * (reflecting gains in internal/external amplifiers */ + return get_p_trxout_eff_mdBm(trx, pout_mdBm); +} |