From 9ae8c496d211155a3f220b63da364fba1a794292 Mon Sep 17 00:00:00 2001
From: Baochen Qiang <quic_bqiang@quicinc.com>
Date: Wed, 20 Sep 2023 16:43:42 +0300
Subject: [PATCH] wifi: ath12k: fix DMA unmap warning on NULL DMA address
Git-commit: 9ae8c496d211155a3f220b63da364fba1a794292
Patch-mainline: v6.7-rc1
References: git-fixes
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@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230830021131.5610-1-quic_bqiang@quicinc.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 8874c815d7fa..16d889fc2043 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);
--
2.35.3