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

[Jeff Johnson]

On 3/26/2025 8:16 AM, Johan Hovold wrote:
> On Wed, Mar 26, 2025 at 08:11:11AM -0700, Jeff Johnson wrote:
>> 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@xxxxxxxxxx>
>>> ---
>>
>> Please make sure to include linux-wireless for all ath.git patches so that
>> they are processed by patchwork.kernel.org
> 
> Ok, I'll try to remember that, but it seems you need to update
> MAINTAINERS to include that list:
> 
> 	$ scripts/get_maintainer.pl 0001-wifi-ath12k-extend-dma-mask-to-36-bits.patch 
> 	Jeff Johnson <jjohnson@xxxxxxxxxx> (supporter:QUALCOMM ATH12K WIRELESS DRIVER)
> 	ath12k@xxxxxxxxxxxxxxxxxxx (open list:QUALCOMM ATH12K WIRELESS DRIVER)
> 	linux-kernel@xxxxxxxxxxxxxxx (open list)
> 
> Do you want me to resend?

no need to resend -- I already picked it up in my 'pending' branch

Let me open a separate thread on the MAINTAINERS issue.

/jeff