Re: [PATCH v3 2/4] wifi: ath12k: use plain access for descriptor length

Baochen Qiang
2025-06-25T01:54:28Z

On 6/17/2025 4:44 PM, Johan Hovold wrote:
> The read memory barrier added by commit 6b67d2cf14ea ("wifi: ath12k: fix
> ring-buffer corruption") is enough to guarantee ordering also for plain
> descriptor accesses if the length helper is ever inlined so drop the
> unnecessary READ_ONCE().
>
> Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
> drivers/net/wireless/ath/ath12k/hal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c
> index f8bd3837b9dc..726969cfcaec 100644
> --- a/drivers/net/wireless/ath/ath12k/hal.c
> +++ b/drivers/net/wireless/ath/ath12k/hal.c
> @@ -1950,7 +1950,7 @@ u32 ath12k_hal_ce_dst_status_get_length(struct hal_ce_srng_dst_status_desc *desc
> {
> u32 len;
>
> - len = le32_get_bits(READ_ONCE(desc->flags), HAL_CE_DST_STATUS_DESC_FLAGS_LEN);
> + len = le32_get_bits(desc->flags, HAL_CE_DST_STATUS_DESC_FLAGS_LEN);
> desc->flags &= ~cpu_to_le32(HAL_CE_DST_STATUS_DESC_FLAGS_LEN);
>
> return len;

Reviewed-by: Baochen Qiang <quic_bqiang@quicinc.com>