Re: [PATCH ath-next] wifi: ath12k: Reduce RX SRNG interrupt timer threshold to 200us

On 6/22/2026 11:53 AM, Thiraviyam Mariyappan wrote:
> Currently when RX traffic is low or intermittent, the RX SRNG interrupt
> mitigation logic defers packet processing for up to 500us via
> HAL_SRNG_INT_TIMER_THRESHOLD_RX.
> 
> This causes excessive RX servicing delay, leading to increased end-to-end
> latency and degraded TCP performance in low-concurrency scenarios.
> 
> In single-client single-stream TCP tests using 5G EHT160 (NSS 2x2) mode,
> throughput drops to ~400 Mbps DL and UL instead of the expected ~600 Mbps.
> 
> In addition, UDP UL end-to-end latency measured in 5G VHT80 (NSS 4x4) mode
> increases by up to ~48% (~570us versus ~270us) across frame sizes from
> 76 to 1518 bytes in uplink and bidirectional traffic, indicating delayed
> RX servicing under sparse traffic conditions.
> 
> To address this issue, reduce the RX SRNG interrupt timer threshold from
> 500us to 200us so that received packets are serviced more promptly under
> low-rate and intermittent RX traffic.
> 
> With this change, single-client single-stream TCP throughput in EHT160 is
> restored to expected levels ~600 Mbps TCP DL/UL and UDP UL end-to-end
> latency in VHT80 returns to baseline values ~270us across all tested frame
> sizes. Under high RX load, no throughput regression is observed, as RX
> rings are already serviced frequently. The primary implication is a modest
> increase in RX interrupt frequency under low traffic, with no observed
> functional, stability, or performance regressions on tested platforms.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01181-QCAHKSWPL_SILICONZ-1
> 
> Signed-off-by: Thiraviyam Mariyappan <[email protected]>

Reviewed-by: Rameshkumar Sundaram <[email protected]>