A second look at a receive slot that cannot be a frame, on the XGS 136 first, 2026-10-31
890: an XGS 107w downloads at 98 to 194 kB/s on a line that gives its owner's other machines 8 MB/s, and its driver refuses or drops about one received frame in five. Its support bundle of 2026-10-31: 158,624 receive descriptors carried a length that cannot be a frame, and 77,721 frames arrived with tag 0 and all-zero metadata where the port tag and the fast path's metadata belong - 236,345 of 1,150,874. Around a two-minute download its owner counted 52,698 more such lengths and 110,185 more frames on no port, of 894,279 received, at 194 kB/s; before it, 85,049 such lengths beside 18,131 good frames. An XGS 107 showed the same two counters in 748, on the same host processor; the XGS 126 and the XGS 136 show neither. Clearing PCIe relaxed ordering and no-snoop (its page) ended an earlier symptom there and not these two.
The whole page, with how it was taken and what it does not show: A second look at a receive slot that cannot be a frame, on the XGS 136 first, 2026-10-31.
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