Improve pipe handling of CMUX modem trace module#194
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Looks promising. Checking the pipe idle before writing all but ensures that the traces will not affect the throughput of data.
However, we are also interested on getting reasonable traces out. I'll run some measurements with the changes.
| * The nrf_modem_lib_trace.c:trace_fragment_write() handles | ||
| * retrying if the backend returns -EAGAIN. | ||
| * | ||
| * It is important to call trace_processed_callback(len) for |
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When CMUX is congested, the trace fifos will easily overflow, and I don't think that there is anything wrong with that. They are dropping traces, same as we are doing here.
I do agree on calling the trace_processed_callback() for every fragment, but that does not ensure the trace fifos not overflowing.
Cherry-pick a usefull helper function from my modem_pipe branch. Signed-off-by: Seppo Takalo <seppo.takalo@nordicsemi.no>
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Improve handling of pipe open-close events of CMUX tracing module. Allow TX timeout to be defined by Kconfig. Remove unnecessary loop from trace backend as nRF library already loops on -EAGAIN. Signed-off-by: Seppo Takalo <seppo.takalo@nordicsemi.no> Signed-off-by: Markus Lassila <markus.lassila@nordicsemi.no>
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Removed Kconfigs, they did not have any effect on trace quality. |
MarkusLassila
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Mar 9, 2026
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Improve handling of pipe open-close events of CMUX tracing module.
Allow TX timeout and drop policy to be defined by Kconfig.
Remove unnecessary loop from trace backend as nRF library already
loops on -EAGAIN.
Attach the pipe from CMUX module, this is cleaner as trace module is enough to just follow pipe events. Does not need to poll CMUX if its started or not.