Restore sync stream after enable_module() re-enables a direction - #2
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wormuz wants to merge 2 commits into
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Restore sync stream after enable_module() re-enables a direction#2wormuz wants to merge 2 commits into
wormuz wants to merge 2 commits into
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libbladeRF tears down the synchronous stream when a direction is
disabled: rfic_host.c calls sync_deinit() on !dir_enable, and bladerf1.c
does the same. That is documented ("this will shut down the underlying
asynchronous stream when enable = false"), but re-enabling the module
does not bring the stream back.
Every later sync_tx()/sync_rx() then fails with
sync tx invalid: not initialized
which gives no hint that sync_config() must be repeated. From the
caller's side the radio simply looks dead: measured on a TX1 -> 50 dB
pad -> RX1 loopback, the received level stopped responding to TX gain
(60 dB and -30 dB both gave -44.4 dB) and 65487 of 66033 transmit calls
failed.
Remember the last sync_config() arguments per direction and replay them
when the module is enabled again. Direction is taken from the low bit:
TX channels are 1 and 3, TX layouts are 1 and 3, RX are even.
Verified on hardware: the disable -> enable -> sync_tx sequence went from
ERR_INVAL to OK, and transmit errors dropped from 65487 to 0.
A stream configured with a *_META format carries per-buffer timestamps and flags. Passing metadata=None leaves libbladeRF with nowhere to report them, so the caller silently loses the timestamp it needs and bladerf_get_timestamp() keeps returning 0. Nothing in the error path points at the cause, so this reads as dead hardware rather than a mismatched call. Measured on a TX1 -> 50 dB pad -> RX1 loopback at 15.36 MSps: with the stream in a metadata format but metadata=None, the frame timestamp stayed at 762229041 across 8 consecutive reads and get_timestamp() returned 0. Consecutive gain steps then analysed the same buffer, so the receive level repeated in pairs (-34.9/-34.9, -20.2/-20.2 dBFS) and a gain ladder that is in fact monotonic came out looking broken. The stream format is already remembered per direction for the enable_module restore path, so the check costs nothing extra: sync_rx()/sync_tx() now raise instead of losing timestamps quietly. After fixing the call sites the same ladder is monotonic, with deviations of +0.1 to +0.8 dB over a 40 dB span.
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libbladeRF tears down the synchronous stream when a direction is disabled:
rfic_host.ccallssync_deinit()on!dir_enable, andbladerf1.cdoes the same. That is documented behaviour — the header says "this will shut down the underlying asynchronous stream whenenable= false" — but re-enabling the module does not bring the stream back.Every later
sync_tx()/sync_rx()then fails withwhich gives no hint that
sync_config()has to be repeated.How it looks from the caller side
The radio simply appears dead. Measured on a TX1 → 50 dB pad → RX1 loopback:
Nothing in the error text points at
enable_module()as the cause, so this reads as broken hardware rather than a lifecycle contract.Fix
Remember the last
sync_config()arguments per direction and replay them when the module is enabled again.Direction is taken from the low bit: TX channels are 1 and 3, TX layouts are 1 and 3, RX are even — verified against the enum values on device.
Verification
On hardware, the previously failing sequence:
became:
and transmit errors over a full probe run dropped from 65487 to 0.