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  • Michal Kazior's avatar
    ath10k: bypass htc for htt tx path · a16942e6
    Michal Kazior authored
    Going through full htc tx path for htt tx is a
    waste of resources. By skipping it it's possible
    to easily submit scatter-gather to the pci hif for
    reduced host cpu load and improved performance.
    The new approach uses dma pool to store the
    following metadata for each tx request:
     * msdu fragment list
     * htc header
     * htt tx command
    The htt tx command contains a msdu prefetch.
    Instead of copying it original mapped msdu address
    is used to submit a second scatter-gather item to
    hif to make a complete htt tx command.
    The htt tx command itself hands over dma mapped
    pointers to msdus and completion of the command
    itself doesn't mean the frame has been sent and
    can be unmapped/freed. This is why htc tx
    completion is skipped for htt tx as all tx related
    resources are freed upon htt tx completion
    indication event (which also implicitly means htt
    tx command itself was completed).
    Since now each htt tx request effectively consists
    of 2 copy engine items CE_HTT_H2T_MSG_SRC_NENTRIES
    is updated to allow maximum of
    TARGET_10X_NUM_MSDU_DESC msdus being queued. This
    keeps the tx path resource management simple.
    Signed-off-by: default avatarMichal Kazior <>
    Signed-off-by: default avatarKalle Valo <>