wifi: ath12k: fix DMA unwind for ext MSDU descriptor retry

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ath12k_wifi7_dp_tx() maps the original MSDU into ti.paddr and
stores the address in skb_cb->paddr. When an extended MSDU descriptor
is used, the function later maps the ext descriptor and overwrites
ti.paddr and ti.data_len with the ext-desc DMA address and length.

If TCL ring allocation then fails, the error path first unmaps the
ext-desc DMA address from skb_cb->paddr_ext_desc. It then falls through
to fail_unmap_dma, which uses ti.paddr/ti.data_len for the original
MSDU unmap. At that point ti.paddr still refers to the ext-desc
mapping, so the ext descriptor is unmapped twice and the original MSDU
mapping is left mapped.

Fix the original MSDU unwind to use skb_cb->paddr and skb->len instead
of ti.paddr/ti.data_len. The ti fields cannot be used after the ext
descriptor is mapped because they are intentionally reused for the
buffer submitted to TCL. Also clear skb_cb->paddr_ext_desc after the
ext-desc unmap so a TCL ring retry cannot observe stale ext-desc DMA
state from the previous attempt.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1

Fixes: 37a068fc9d ("wifi: ath12k: Handle error cases during extended skb allocation")
Signed-off-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260813-ext-msdu-fix-v1-1-c5e80ccd061a@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

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Rameshkumar Sundaram 2026-08-13 23:09:20 +05:30 • committed by Jeff Johnson

parent 507478f6f9

commit 4de5a8a0ed

1 changed files with 4 additions and 2 deletions

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drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c

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