On Thu, 22 Aug 2024, Stuart wrote:

quoted

If I recollect correctly, there may be an alignment issue and just using
the stack is not enough to guaranty what is needed.

I can't find any reference to issues with it, I'm not sure what I saw before.
Also, it seems like the hid-asus driver is using it:
https://elixir.bootlin.com/linux/v6.11-rc4/source/drivers/hid/hid-asus.c#L391

You can't do DMA from stack; see section "What memory is DMA'able?" of 
Documentation/core-api/dma-api-howto.rst

-- 
Jiri Kosina
SUSE Labs