Re: [PATCH ath-next v4] wifi: ath12k: avoid dynamic alloc when parsing wmi tb

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

On 3/23/2026 5:40 AM, Rameshkumar Sundaram wrote:
> On 3/19/2026 9:29 PM, Jeff Johnson wrote:
>> On 3/19/2026 7:35 AM, Nicolas Escande wrote:
>>> On Thu Mar 19, 2026 at 12:08 PM CET, Rameshkumar Sundaram wrote:
>>>> Or may be have this allocated on first device probe and free it on last
>>>> device deinit ?
>>>
>>> That seems even more involved. It would be easier to go back to the previous
>>> version and simply, alloc it once per ath12k_base
>>>
>>> What do you guys think ?
>>>
>>
>> Going back to that may be the better solution. It isn't nice that this current
>> solution may allocate memory when the driver isn't actually used. But I'll let
>> others on the team weigh in as well.
>>
> 
> Yeah, allocating once per ath12k_base is definitely the simpler 
> ownership model.
> I was only wondering whether sharing it across devices might be worth a 
> look, since this is per-CPU scratch space and the table itself is fairly 
> large.

The other alternative is to still have a single global allocation, but also
keep a reference count that starts at 0. when each ar starts it calls a single
api to alloc the memory and when it stops it calls another api to dealloc the
memory

when the first ar starts and calls the alloc api, the refcount will be 0 so it
will allocate the memory and increment the refcount to 1. when any subsequent
ars start and call the alloc api, it will just increment the ref count. on
deinit each ar will call the dealloc api. this api will just decrement the
refcount until it reaches 0 at which time the memory is freed.