From patchwork Wed Jun 4 14:45:06 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 894407 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5DFDF32C85; Wed, 4 Jun 2025 14:45:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749048349; cv=none; b=T03IIDVE1Pd1yhydhlCSWGJI9J5mnl5UcQe/YhAqcAYFnV7DnjtOEaG3Yz0Dh9iS6nmYePx5AJ15X/VVNQPtvqKI3yjCvpK0r5J1/M8Y+gBGNBt4f9QVXw8q4AyX3dR4wHKQtOKPfsQutHrC45zZoWZlQki7i/CSeJUXLMnMfNk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749048349; c=relaxed/simple; bh=AahTbiL0j1lHqgp6tMq8JeHQ5K8h8e6zfnJJYbWsUc0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fcEMHvQ5TgjxBkZhS/41HSjePhOpBYtZ66UgPhso+GvDvmcVl7YaEIW1GBetKLXz9Wn9PdQsnuf4kaID6vOzW2b2rUwcvoUBBE4L89+7v1vwJWM0XcWuxNwZNlfQpvXbRXrG35D69oYa93HXFVG8uQaj7dGtivTMm2+fpKQrzc8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bHv8Tzxa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bHv8Tzxa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E2ABC4CEF1; Wed, 4 Jun 2025 14:45:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749048349; bh=AahTbiL0j1lHqgp6tMq8JeHQ5K8h8e6zfnJJYbWsUc0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bHv8TzxaZHukiEWdht1QcuRlHO9xmK/M+5GLLPyEstC2Ehyn++Usz8tx2FV+mpjG2 pXjvObsHHKorU8W6CbN1kGvZUi1Z+7Ca+bqSJQBBF+ZuvwwgexQhA9wi/zoSn1Fq8l Nw12m1EGo6aFwPdBtLI7LaAiPafjAgw6ihZo38dYkyH4aI3JjO2cseTSyDE3vujzBY nK+s0LzaLKlEmdqBPKpsGp+8sgySANx3/FEhDOmslVL6MLYTR78ymUNI6IA57rTDXs 0sGtzvH5Ih1CroG5x+HEZUu5peIjVsE7P/i0C8XXeREs/rGW5etxoFbTHOdXkwNyWy VRqWXddF2Qbbg== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1uMpND-000000007OY-0oJh; Wed, 04 Jun 2025 16:45:47 +0200 From: Johan Hovold To: Jeff Johnson Cc: Miaoqing Pan , Remi Pommarel , Baochen Qiang , linux-wireless@vger.kernel.org, ath12k@lists.infradead.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH v2 1/4] wifi: ath12k: fix dest ring-buffer corruption Date: Wed, 4 Jun 2025 16:45:06 +0200 Message-ID: <20250604144509.28374-2-johan+linaro@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250604144509.28374-1-johan+linaro@kernel.org> References: <20250604144509.28374-1-johan+linaro@kernel.org> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add the missing memory barrier to make sure that destination ring descriptors are read after the head pointers to avoid using stale data on weakly ordered architectures like aarch64. The barrier is added to the ath12k_hal_srng_access_begin() helper for symmetry with follow-on fixes for source ring buffer corruption which will add barriers to ath12k_hal_srng_access_end(). Note that this may fix the empty descriptor issue recently worked around by commit 51ad34a47e9f ("wifi: ath12k: Add drop descriptor handling for monitor ring"). Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Cc: stable@vger.kernel.org # 6.3 Signed-off-by: Johan Hovold --- drivers/net/wireless/ath/ath12k/ce.c | 3 --- drivers/net/wireless/ath/ath12k/hal.c | 17 ++++++++++++++--- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/ce.c b/drivers/net/wireless/ath/ath12k/ce.c index 740586fe49d1..b66d23d6b2bd 100644 --- a/drivers/net/wireless/ath/ath12k/ce.c +++ b/drivers/net/wireless/ath/ath12k/ce.c @@ -343,9 +343,6 @@ static int ath12k_ce_completed_recv_next(struct ath12k_ce_pipe *pipe, goto err; } - /* Make sure descriptor is read after the head pointer. */ - dma_rmb(); - *nbytes = ath12k_hal_ce_dst_status_get_length(desc); *skb = pipe->dest_ring->skb[sw_index]; diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c index 91d5126ca149..9eea13ed5565 100644 --- a/drivers/net/wireless/ath/ath12k/hal.c +++ b/drivers/net/wireless/ath/ath12k/hal.c @@ -2126,13 +2126,24 @@ void *ath12k_hal_srng_src_get_next_reaped(struct ath12k_base *ab, void ath12k_hal_srng_access_begin(struct ath12k_base *ab, struct hal_srng *srng) { + u32 hp; + lockdep_assert_held(&srng->lock); - if (srng->ring_dir == HAL_SRNG_DIR_SRC) + if (srng->ring_dir == HAL_SRNG_DIR_SRC) { srng->u.src_ring.cached_tp = *(volatile u32 *)srng->u.src_ring.tp_addr; - else - srng->u.dst_ring.cached_hp = READ_ONCE(*srng->u.dst_ring.hp_addr); + } else { + hp = READ_ONCE(*srng->u.dst_ring.hp_addr); + + if (hp != srng->u.dst_ring.cached_hp) { + srng->u.dst_ring.cached_hp = hp; + /* Make sure descriptor is read after the head + * pointer. + */ + dma_rmb(); + } + } } /* Update cached ring head/tail pointers to HW. ath12k_hal_srng_access_begin()