regression in ath10k dma allocation

[Tobias Klausmann]

Hello all,

within the current development cycle i noted the ath10k driver failing 
to setup:

[ÂÂÂ 3.185660] ath10k_pci 0000:02:00.0: failed to alloc CE dest ring 1: -12
[ÂÂÂ 3.185664] ath10k_pci 0000:02:00.0: failed to allocate copy engine 
pipe 1: -12
[ÂÂÂ 3.185667] ath10k_pci 0000:02:00.0: failed to allocate copy engine 
pipes: -12
[ÂÂÂ 3.185669] ath10k_pci 0000:02:00.0: failed to setup resource: -12
[ÂÂÂ 3.185692] ath10k_pci: probe of 0000:02:00.0 failed with error -12

the actual failure comes from [1] and indeed bisecting brought me to a 
related commit "dma-contiguous: add dma_{alloc,free}_contiguous() 
helpers" [2]. Reverting the commit fixes the problem, yet this might 
just be the driver abusing the dma infrastructure, so hopefully someone 
can have a look at it, as i'm not familiar with the code!


[1]: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/ath/ath10k/ce.c?h=v5.3-rc4#n1650

[2]: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b1d2dc009dece4cd7e629419b52266ba51960a6b


Greetings,

Tobias