tbf: Fix downlink packet loss

When the MS is pinged with a longer interval, many packets get lost
even if the GprsMs object is kept. If the interval is above the time
where the DL TBF is in state FLOW (mainly influenced be the
dl-tbf-idle-time command), an new TBF must be requested via AGCH for
each ICMP PING message.

Currently the LLC frame containing the PING is immediately stored
in the TBF and gets lost, if TBF establishment fails for some reason.

This commit moves all calls to put_frame() to schedule_next_frame(),
where the data is moved from the LLC queue to the frame storage
within the TBF object. This method is only called from within
create_new_bsn() when the TBF is in the FLOW state and the frame is
going to be encoded immediately.

At all other places, where put_frame() has been called before, the
LLC message is just appended to the LLC queue in the GprsMs object.
This change effectively simplifies the related code parts, since
date/len information and discard notifications is no longer needed
there.

Ticket: #1759
Sponsored-by: On-Waves ehf

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 5bc492ec..5dfd2b8e 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -486,10 +486,10 @@ static void test_tbf_dl_llc_loss()
 		msg = ms->dl_tbf()->create_dl_acked_block(fn += 4, 7);
 		fprintf(stderr, "MSG = %s\n", msgb_hexdump(msg));
 		OSMO_ASSERT(msgb_length(msg) == 23);
-		/* OSMO_ASSERT(msgb_data(msg)[10] == expected_data); */
+		OSMO_ASSERT(msgb_data(msg)[10] == expected_data);
 		expected_data += 1;
 	}
-	/* OSMO_ASSERT(expected_data-1 == 3); */
+	OSMO_ASSERT(expected_data-1 == 3);
 
 	printf("=== end %s ===\n", __func__);