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Sun, 19 Jul 2026 14:58:25 -0700 (PDT) Received: from nv-msd-x1c.mtdk.labs.mlnx ([212.60.125.8]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c16eb80bbf8sm379116766b.0.2026.07.19.14.58.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 19 Jul 2026 14:58:25 -0700 (PDT) From: Mark Ruvald Pedersen To: linux-wireless@vger.kernel.org Cc: Jeff Johnson , ath11k@lists.infradead.org Subject: [RFC PATCH 1/3] wifi: ath11k: reserve headroom when aligning RX buffers Date: Sun, 19 Jul 2026 23:58:15 +0200 Message-ID: <20260719215817.2468580-2-wabsie@gmail.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20260719215817.2468580-1-wabsie@gmail.com> References: <20260719215817.2468580-1-wabsie@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260719_145828_081601_88517F31 X-CRM114-Status: UNSURE ( 7.86 ) X-CRM114-Notice: Please train this message. X-BeenThere: ath11k@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "ath11k" Errors-To: ath11k-bounces+ath11k=archiver.kernel.org@lists.infradead.org RXDMA buffers are allocated with extra space for 128-byte alignment, but the driver tries to move skb->data with skb_pull(). The skb is empty at that point, so skb_pull() rejects every positive delta and leaves the data pointer unchanged. Use skb_reserve() while the skb is empty. The existing extra allocation space leaves at least DP_RX_BUFFER_SIZE bytes of DMA tailroom after the reservation. Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.9.0.1-02146-QCAHKSWPL_SILICONZ-1 Signed-off-by: Mark Ruvald Pedersen --- diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c index 33425707c..e4ea0c216 100644 --- a/drivers/net/wireless/ath/ath11k/dp_rx.c +++ b/drivers/net/wireless/ath/ath11k/dp_rx.c @@ -378,7 +378,7 @@ int ath11k_dp_rxbufs_replenish(struct ath11k_base *ab, int mac_id, if (!IS_ALIGNED((unsigned long)skb->data, DP_RX_BUFFER_ALIGN_SIZE)) { - skb_pull(skb, - PTR_ALIGN(skb->data, DP_RX_BUFFER_ALIGN_SIZE) - - skb->data); + skb_reserve(skb, + PTR_ALIGN(skb->data, DP_RX_BUFFER_ALIGN_SIZE) - + skb->data); } @@ -2875,7 +2875,7 @@ static struct sk_buff *ath11k_dp_rx_alloc_mon_status_buf(struct ath11k_base *ab, if (!IS_ALIGNED((unsigned long)skb->data, DP_RX_BUFFER_ALIGN_SIZE)) { - skb_pull(skb, PTR_ALIGN(skb->data, DP_RX_BUFFER_ALIGN_SIZE) - + skb_reserve(skb, PTR_ALIGN(skb->data, DP_RX_BUFFER_ALIGN_SIZE) - skb->data); }