From 5b70b8c0be2b9f78268cdb76084a56524bf7f259 Mon Sep 17 00:00:00 2001 From: Baochen Qiang Date: Wed, 20 Sep 2023 16:43:42 +0300 Subject: [PATCH] wifi: ath12k: fix DMA unmap warning on NULL DMA address [ Upstream commit 9ae8c496d211155a3f220b63da364fba1a794292 ] In ath12k_dp_tx(), if we reach fail_dma_unmap due to some errors, current code does DMA unmap unconditionally on skb_cb->paddr_ext_desc. However, skb_cb->paddr_ext_desc may be NULL and thus we get below warning: kernel: [ 8887.076212] WARNING: CPU: 3 PID: 0 at drivers/iommu/dma-iommu.c:1077 iommu_dma_unmap_page+0x79/0x90 Fix it by checking skb_cb->paddr_ext_desc before unmap it. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Signed-off-by: Baochen Qiang Acked-by: Jeff Johnson Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230830021131.5610-1-quic_bqiang@quicinc.com Signed-off-by: Sasha Levin --- drivers/net/wireless/ath/ath12k/dp_tx.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/dp_tx.c b/drivers/net/wireless/ath/ath12k/dp_tx.c index 8874c81..16d889f 100644 --- a/drivers/net/wireless/ath/ath12k/dp_tx.c +++ b/drivers/net/wireless/ath/ath12k/dp_tx.c @@ -330,8 +330,11 @@ tcl_ring_sel: fail_unmap_dma: dma_unmap_single(ab->dev, ti.paddr, ti.data_len, DMA_TO_DEVICE); - dma_unmap_single(ab->dev, skb_cb->paddr_ext_desc, - sizeof(struct hal_tx_msdu_ext_desc), DMA_TO_DEVICE); + + if (skb_cb->paddr_ext_desc) + dma_unmap_single(ab->dev, skb_cb->paddr_ext_desc, + sizeof(struct hal_tx_msdu_ext_desc), + DMA_TO_DEVICE); fail_remove_tx_buf: ath12k_dp_tx_release_txbuf(dp, tx_desc, pool_id); -- 2.7.4