This series fixes a stability issue in the flow scheduling Tx send/clean path that results in a Tx timeout.
The existing guardrails in the Tx path were not sufficient to prevent the driver from reusing completion tags that were still in flight (held by the HW). This collision would cause the driver to erroneously clean the wrong packet thus leaving the descriptor ring in a bad state. The main point of this refactor is to replace the flow scheduling buffer ring with a large pool/array of buffers. The completion tag then simply is the index into this array. The driver tracks the free tags and pulls the next free one from a refillq. The cleaning routines simply use the completion tag from the completion descriptor to index into the array to quickly find the buffers to clean. All of the code to support the refactor is added first to ensure traffic still passes with each patch. The final patch then removes all of the obsolete stashing code. --- v2: - Add a new patch "idpf: simplify and fix splitq Tx packet rollback error path" that fixes a bug in the error path. It also sets up changes in patch 4 that are necessary to prevent a crash when a packet rollback occurs using the buffer pool. v1: https://lore.kernel.org/intel-wired-lan/[email protected]/T/#maf9f464c598951ee860e5dd24ef8a451a488c5a0 Joshua Hay (6): idpf: add support for Tx refillqs in flow scheduling mode idpf: improve when to set RE bit logic idpf: simplify and fix splitq Tx packet rollback error path idpf: replace flow scheduling buffer ring with buffer pool idpf: stop Tx if there are insufficient buffer resources idpf: remove obsolete stashing code .../ethernet/intel/idpf/idpf_singleq_txrx.c | 61 +- drivers/net/ethernet/intel/idpf/idpf_txrx.c | 723 +++++++----------- drivers/net/ethernet/intel/idpf/idpf_txrx.h | 87 +-- 3 files changed, 356 insertions(+), 515 deletions(-) -- 2.39.2
