Attention is currently required from: Hoernchen, laforge, tempest, tnt, ttsou.
Hello Hoernchen, Jenkins Builder, laforge, tnt, ttsou,
I'd like you to reexamine a change. Please visit
https://gerrit.osmocom.org/c/osmo-trx/+/41231?usp=email
to look at the new patch set (#2).
The following approvals got outdated and were removed:
Code-Review+1 by Hoernchen, Code-Review+1 by laforge
Change subject: trx: Fix tx/rx-sps 4 for USRP1 devices
......................................................................
trx: Fix tx/rx-sps 4 for USRP1 devices
The existing code sets the pingOffset variable to -7231(269 - 7500)
with tx-sps = 4. The (apparent) correct value for pingOffset for
tx/rx-sps 4 is 272.
While I'm not completely sure how this patch works to fix the increased
sps value, my theory is that the original OpenBTS TRX only supported
a split sps setup(tx-sps=4, rx_sps=1 for sps=4), which created
differing decimation rates between Tx and Rx on the board.
In this case, apparently you needed to account for an advance in the
timestamp for a correct output.
With tx_sps == rx_sps, the decimation/sample rates will be the same,
and(I guess) this advance doesn't need to be accounted for.
Also changed a line in the initialization of the Rx end of the USRP
device to use the correct decimation rate when tx/rx-sps == 4.
Since osmo-trx won't allow nonequal values for tx-sps and rx-sps, I
commented out the logic that selected pingOffset based on sps.
I left it visible in the file for reference however.
Tested & working on the URAN-1, a USRP1 clone designed for GSM.
Change-Id: I3b08c23a3e7d4a226cd23b9fe42558f596a63257
---
M Transceiver52M/device/usrp1/USRPDevice.cpp
1 file changed, 8 insertions(+), 7 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-trx refs/changes/31/41231/2
--
To view, visit https://gerrit.osmocom.org/c/osmo-trx/+/41231?usp=email
To unsubscribe, or for help writing mail filters, visit
https://gerrit.osmocom.org/settings?usp=email
Gerrit-MessageType: newpatchset
Gerrit-Project: osmo-trx
Gerrit-Branch: master
Gerrit-Change-Id: I3b08c23a3e7d4a226cd23b9fe42558f596a63257
Gerrit-Change-Number: 41231
Gerrit-PatchSet: 2
Gerrit-Owner: tempest <[email protected]>
Gerrit-Reviewer: Hoernchen <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <[email protected]>
Gerrit-Reviewer: tnt <[email protected]>
Gerrit-Reviewer: ttsou <[email protected]>
Gerrit-CC: fixeria <[email protected]>
Gerrit-CC: pespin <[email protected]>
Gerrit-Attention: Hoernchen <[email protected]>
Gerrit-Attention: laforge <[email protected]>
Gerrit-Attention: tempest <[email protected]>
Gerrit-Attention: tnt <[email protected]>
Gerrit-Attention: ttsou <[email protected]>
