Re: [PATCH v2 15/22] wifi: ath12k: add BDF address in hardware parameter

[Konrad Dybcio]

On 6.12.2024 5:34 AM, Raj Kumar Bhagat wrote:
> On 12/5/2024 11:12 PM, Konrad Dybcio wrote:
>> On 3.12.2024 10:18 AM, Raj Kumar Bhagat wrote:
>>> On 11/4/2024 7:46 PM, Konrad Dybcio wrote:
>>>> On 15.10.2024 8:26 PM, Raj Kumar Bhagat wrote:
>>>>> The Ath2k AHB device (IPQ5332) firmware requests BDF_MEM_REGION_TYPE
>>>>> memory during QMI memory requests. This memory is part of the
>>>>> HOST_DDR_REGION_TYPE. Therefore, add the BDF memory address to the
>>>>> hardware parameter and provide this memory address to the firmware
>>>>> during QMI memory requests.
>>>>
>>>> Sounds like something to put in the device tree, no?
>>>>
>>>
>>> This BDF memory address is the RAM offset. We did add this in device tree in
>>> version 1. This is removed from device tree in v2 based on the review comment that
>>> DT should not store RAM offset.
>>>
>>> refer below link:
>>> Link: https://lore.kernel.org/all/f8cd9c3d-47e1-4709-9334-78e4790acef0@xxxxxxxxxx/
>>
>> Right, I think this could be something under /reserved-memory instead
>>
> 
> Thanks for the suggestion. However, the BDF_MEM_REGION_TYPE is already within the
> memory reserved for HOST_DDR_REGION_TYPE through /reserved-memory. Therefore, reserving
> the memory for BDF_MEM_REGION_TYPE again in the Device Tree (DT) will cause a warning
> for 'overlapping memory reservation'.

Then you can grab a handle to it with of_reserved_mem_lookup()
and of_reserved_mem_device_init_by_idx()

Konrad