Re: [PATCH ath-next] wifi: ath12k: fix truncated TX buffer DMA address in MSDU ext descriptor
Rameshkumar Sundaram <[email protected]>
| Newsgroups | org.infradead.lists.ath12k,org.kernel.vger.linux-wireless |
|---|---|
| Message-ID | <[email protected]> |
On 8/18/2026 7:33 AM, Baochen Qiang wrote:
> ath12k_wifi7_hal_tx_cmd_ext_desc_setup() programs the low 32 bits of the
> TX buffer physical address into HAL_TX_MSDU_EXT_INFO0_BUF_PTR_LO but
> hardcodes the high bits field HAL_TX_MSDU_EXT_INFO1_BUF_PTR_HI to 0x0.
>
> dma_addr_t is 64-bit on platforms with CONFIG_ARCH_DMA_ADDR_T_64BIT, so
> whenever a TX buffer is mapped above the 4 GB boundary the upper bits of
> paddr are dropped and the firmware is handed a truncated address,
> leading to potential TX failures.
>
> Write the upper bits of paddr into BUF_PTR_HI to fix this issue.
>
> Issue found during code review, compile tested only.
>
> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> Signed-off-by: Baochen Qiang <[email protected]>
Reviewed-by: Rameshkumar Sundaram <[email protected]>