Change in osmo-bts[master]: common: tx_power: Fix bug in power ramp up below max-initial value

[pespin]

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/19703 )


Change subject: common: tx_power: Fix bug in power ramp up below max-initial value
......................................................................

common: tx_power: Fix bug in power ramp up below max-initial value

See previous commit adding the unit test about the error description and
expected behavior.

The wrong behavior appeared due to step_size_mdB being unsigned and the
whole addition at the left side of the comparison being turned too as
unsigned, hence a small negative value turning into a big positive
value, and tpp->p_total_cur_mdBm not being updated to speed up the power
ramping.

Change-Id: I36a34362ebc90226fd8e1e190f898c3718fd923a
---
M src/common/tx_power.c
M tests/tx_power/tx_power_test.ok
2 files changed, 1 insertion(+), 5 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/03/19703/1

diff --git a/src/common/tx_power.c b/src/common/tx_power.c
index c5ea7ed..08c4236 100644
--- a/src/common/tx_power.c
+++ b/src/common/tx_power.c
@@ -278,7 +278,7 @@
 		} else {
 			/* We need to step it up. Start from the current value, shortcutting to max-initial. */
 			/* Set attenuation to cause no power change right now */
-			if (tpp->p_total_cur_mdBm + tpp->ramp.step_size_mdB < tpp->ramp.max_initial_pout_mdBm)
+			if (tpp->p_total_cur_mdBm + (int)tpp->ramp.step_size_mdB < tpp->ramp.max_initial_pout_mdBm)
 				tpp->p_total_cur_mdBm = tpp->ramp.max_initial_pout_mdBm - tpp->ramp.step_size_mdB;
 			tpp->ramp.attenuation_mdB = tpp->p_total_tgt_mdBm - tpp->p_total_cur_mdBm;
 
diff --git a/tests/tx_power/tx_power_test.ok b/tests/tx_power/tx_power_test.ok
index ec3ea61..c8f0441 100644
--- a/tests/tx_power/tx_power_test.ok
+++ b/tests/tx_power/tx_power_test.ok
@@ -23,10 +23,6 @@
 CHANGE_POWER(23000)
 power_ramp finished
 Testing tx_power ramping for osmo-bts-trx after lock
-CHANGE_POWER(-8000)
-CHANGE_POWER(-6000)
-CHANGE_POWER(-4000)
-CHANGE_POWER(-2000)
 CHANGE_POWER(0)
 CHANGE_POWER(2000)
 CHANGE_POWER(4000)

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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I36a34362ebc90226fd8e1e190f898c3718fd923a
Gerrit-Change-Number: 19703
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin at sysmocom.de>
Gerrit-MessageType: newchange
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