Re: [PATCH] wifi: ath12k: extend dma mask to 36 bits

[Jeff Johnson <jeff.johnson@oss.qualcomm.com>]

On 3/21/2025 9:23 AM, Johan Hovold wrote:
> Extend the DMA mask to 36 bits to avoid using bounce buffers on machines
> without an iommu (under OS control) similar to what was done for ath11k
> in commit dbd73acb22d8 ("wifi: ath11k: enable 36 bit mask for stream
> DMA").
> 
> This specifically avoids using bounce buffers on Qualcomm Snapdragon X
> Elite machines like the Lenovo ThinkPad T14s when running at EL1.
> 
> Note that the mask could possibly be extended further but unresolved DMA
> issues with 64 GiB X Elite machines currently prevents that from being
> tested.
> 
> Also note that the driver is limited to 32 bits for coherent
> allocations and that there is no need to check for errors when setting
> masks larger than 32 bits.
> 
> Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---

Please make sure to include linux-wireless for all ath.git patches so that
they are processed by patchwork.kernel.org

/jeff