Commit e834da4c authored by Johan Hovold's avatar Johan Hovold Committed by Jeff Johnson
Browse files

wifi: ath12k: fix source ring-buffer corruption 



Add the missing memory barrier to make sure that LMAC source ring
descriptors are written before updating the head pointer to avoid
passing stale data to the firmware on weakly ordered architectures like
aarch64.

Note that non-LMAC rings use MMIO write accessors which have the
required write memory barrier.

Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: d8899132 ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Cc: stable@vger.kernel.org      # 6.3
Signed-off-by: default avatarJohan Hovold <johan+linaro@kernel.org>
Reviewed-by: default avatarBaochen Qiang <quic_bqiang@quicinc.com>
Link: https://patch.msgid.link/20250617084402.14475-4-johan+linaro@kernel.org


Signed-off-by: default avatarJeff Johnson <jeff.johnson@oss.qualcomm.com>
parent 79390f61

drivers/net/wireless/ath/ath12k/hal.c

+9 −1
Original line number Diff line number Diff line
@@ -2178,7 +2178,11 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) 
		if (srng->ring_dir == HAL_SRNG_DIR_SRC) {

			srng->u.src_ring.last_tp =

				*(volatile u32 *)srng->u.src_ring.tp_addr;

			*srng->u.src_ring.hp_addr = srng->u.src_ring.hp;

			/* Make sure descriptor is written before updating the

			 * head pointer.

			 */

			dma_wmb();

			WRITE_ONCE(*srng->u.src_ring.hp_addr, srng->u.src_ring.hp);

		} else {

			srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr;

			*srng->u.dst_ring.tp_addr = srng->u.dst_ring.tp;
@@ -2187,6 +2191,10 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) 
		if (srng->ring_dir == HAL_SRNG_DIR_SRC) {

			srng->u.src_ring.last_tp =

				*(volatile u32 *)srng->u.src_ring.tp_addr;

			/* Assume implementation use an MMIO write accessor

			 * which has the required wmb() so that the descriptor

			 * is written before the updating the head pointer.

			 */

			ath12k_hif_write32(ab,

					   (unsigned long)srng->u.src_ring.hp_addr -

					   (unsigned long)ab->mem,