The XGS 136's receive rings on the coprocessor's doorbells, 2026-10-20¶
Until today the XGS 136's host emptied its receive rings on a clock: every millisecond since
2026-10-17, and only then. The coprocessor has
four target-to-host doorbells for the GIU - MSI-X vectors the driver allocated and counted - and they
never rang, because every receive queue was added with msix_id 0. The vendor's own host driver runs
its receive on them by default (msix_mode 1, "Rx"), giving queue q the facility's doorbell q,
whose id is that vector's place in the order the vectors are allocated in.
The whole page, with how it was taken and what it does not show: The XGS 136's receive rings on the coprocessor's doorbells, 2026-10-20.
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