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

[Vasanthakumar Thiagarajan]

Adding original to and cc list back.

When replying please keep all the email addresses as in the original mail.

On 3/25/2025 12:34 PM, Raj Kumar Bhagat wrote:
> On 3/21/2025 9:53 PM, 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
>
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
>
> Tested-by: Raj Kumar Bhagat <quic_rajkbhag@xxxxxxxxxxx>
>
> Validated iperf traffic on QCN9274 with FW version -
> WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1