• Rajkumar Manoharan's avatar
    ath10k: implement NAPI support · 3c97f5de
    Rajkumar Manoharan authored
    Add NAPI support for rx and tx completion. NAPI poll is scheduled
    from interrupt handler. The design is as below
    
     - on interrupt
         - schedule napi and mask interrupts
     - on poll
       - process all pipes (no actual Tx/Rx)
       - process Rx within budget
       - if quota exceeds budget reschedule napi poll by returning budget
       - process Tx completions and update budget if necessary
       - process Tx fetch indications (pull-push)
       - push any other pending Tx (if possible)
       - before resched or napi completion replenish htt rx ring buffer
       - if work done < budget, complete napi poll and unmask interrupts
    
    This change also get rid of two tasklets (intr_tq and txrx_compl_task).
    
    Measured peak throughput with NAPI on IPQ4019 platform in controlled
    environment. No noticeable reduction in throughput is seen and also
    observed improvements in CPU usage. Approx. 15% CPU usage got reduced
    in UDP uplink case.
    
    DL: AP DUT Tx
    UL: AP DUT Rx
    
    IPQ4019 (avg. cpu usage %)
    
    ========
                    TOT              +NAPI
                  ===========      =============
    TCP DL       644 Mbps (42%)    645 Mbps (36%)
    TCP UL       673 Mbps (30%)    675 Mbps (26%)
    UDP DL       682 Mbps (49%)    680 Mbps (49%)
    UDP UL       720 Mbps (28%)    717 Mbps (11%)
    Signed-off-by: default avatarRajkumar Manoharan <rmanohar@qti.qualcomm.com>
    Signed-off-by: default avatarKalle Valo <kvalo@qca.qualcomm.com>
    3c97f5de
ahb.c 22.3 KB