Re: [PATCH v5 07/13] wifi: ath12k: add support for fixed QMI firmware memory

[Raj Kumar Bhagat <quic_rajkbhag@quicinc.com>]

On 2/3/2025 3:42 PM, Krzysztof Kozlowski wrote:
> On 03/02/2025 10:44, Raj Kumar Bhagat wrote:
>> On 1/30/2025 1:16 PM, Krzysztof Kozlowski wrote:
>>> On 30/01/2025 05:35, Raj Kumar Bhagat wrote:
>>>> @@ -2646,6 +2663,136 @@ static int ath12k_qmi_alloc_target_mem_chunk(struct ath12k_base *ab)
>>>>  	return ret;
>>>>  }
>>>>  
>>>> +static int ath12k_qmi_assign_target_mem_chunk(struct ath12k_base *ab)
>>>> +{
>>>> +	struct device_node *mem_node;
>>>> +	struct resource res, m3_res;
>>>> +	u32 bdf_start_addr;
>>>> +	int i, idx, ret;
>>>> +
>>>> +	for (i = 0, idx = 0; i < ab->qmi.mem_seg_count; i++) {
>>>> +		switch (ab->qmi.target_mem[i].type) {
>>>> +		case HOST_DDR_REGION_TYPE:
>>>> +			mem_node = ath12k_core_get_reserved_mem_by_name(ab, "q6-region");
>>>
>>>
>>> Why cannot you use existing API for reserved memory -
>>> of_reserved_mem_lookup()?
>>>
>>
>> The of_reserved_mem_lookup() requires reserved memory node to read the memory and
>> return in the structure "struct reserved_mem".
>>
>> The of_reserved_mem_lookup() would be used after we get the reserved memory node
>> using the API - ath12k_core_get_reserved_mem_by_name(ab, "q6-region");
>>
>> In next version we would use of_reserved_mem_lookup(), Something like below:
>>     mem_node = ath12k_core_get_reserved_mem_by_name(ab, "q6-region");
> 
> Then why do you need ath12k_core_get_reserved_mem_by_name() in the first
> place? Just use of_reserved_mem_lookup() directly. Why do you need to
> parse phandle before of_reserved_mem_lookup()?
> 

Sorry, I'm having difficulty understanding this.
We have the WiFi node at ab->dev->of_node, but we don't have a node for the reserved-memory
'q6-region'. The of_reserved_mem_lookup() function requires the device node for 'q6-region'.

Could you please suggest how we can use of_reserved_mem_lookup() without obtaining the
'q6-region' node first.