This is a note to let you know that I've just added the patch titled wifi: ath12k: fix DMA unmap warning on NULL DMA address to the 6.5-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-ath12k-fix-dma-unmap-warning-on-null-dma-addres.patch and it can be found in the queue-6.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ede4a6b1bd64cbbf995ea506dc45bd231ba08c68 Author: Baochen Qiang <quic_bqiang@xxxxxxxxxxx> Date: Wed Sep 20 16:43:42 2023 +0300 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 <quic_bqiang@xxxxxxxxxxx> Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20230830021131.5610-1-quic_bqiang@xxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/ath/ath12k/dp_tx.c b/drivers/net/wireless/ath/ath12k/dp_tx.c index d3c7c76d6b75e..5d1be6451d587 100644 --- a/drivers/net/wireless/ath/ath12k/dp_tx.c +++ b/drivers/net/wireless/ath/ath12k/dp_tx.c @@ -330,8 +330,11 @@ int ath12k_dp_tx(struct ath12k *ar, struct ath12k_vif *arvif, 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);