wifi: ath12k: place dp_mon_mpdu on stack in mon dst reap loop

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ath12k_wifi7_dp_rx_mon_dest_process() allocates a dp_mon_mpdu with
kzalloc(GFP_ATOMIC) for each delivered MPDU. On allocation failure
it breaks out of the reap loop without calling
ath12k_hal_srng_dst_get_next_entry(), leaving the destination ring
tail pointer parked on the current entry -- the same entry will
be peek()ed on every subsequent NAPI schedule, stalling monitor
RX until the mon_dest_ring_stuck_cnt recovery path resyncs the
PPDU ID. The head_msdu chain accumulated for this iteration is
also orphaned since the break bypasses both the delivery and
the cleanup paths.

kmemleak reports these skbs in field testing:
  kmemleak_alloc()
  __netdev_alloc_skb()
  ath12k_dp_rx_bufs_replenish()
  ath12k_wifi7_dp_rx_mon_dest_process()

dp_mon_mpdu is used only within a single reap loop iteration and
is passed synchronously to ath12k_wifi7_dp_mon_rx_deliver(); the
callee does not retain the pointer. Place it on the stack instead
of using kzalloc(GFP_ATOMIC). This eliminates the allocation
failure path (and the ring stall it caused) and saves a
kzalloc/kfree pair per delivered MPDU.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3

Fixes: 72bfbf19b7 ("wifi: ath12k: add support to reap and process mon dest ring")
Signed-off-by: Kang Yang <kang.yang@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20260916060325.854-5-kang.yang@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

...

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Kang Yang 2026-09-16 14:03:23 +08:00 • committed by Jeff Johnson

parent 1a10a55855

commit 8b1d2f4c38

1 changed files with 8 additions and 11 deletions

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drivers/net/wireless/ath/ath12k/wifi7/dp_mon.c

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