Re: [PATCH v2 4/5] ALSA: emu10k1: make sure synth DMA pages are allocated with DMA functions

[Maciej S. Szmigiero]

On 12.02.2018 13:44, Takashi Iwai wrote:
> On Sat, 27 Jan 2018 15:42:47 +0100,
>  Maciej S. Szmigiero  wrote:
>>
>> Commit a5003fc04113 ("[ALSA] emu10k1 - simplify page allocation for synth")
>> switched from using the DMA allocator for synth DMA pages to manually
>> calling alloc_page().
>> However, this usage has an implicit assumption that the DMA address space
>> for the emu10k1-family chip is the same as the CPU physical address space
>> which is not true for a system with a IOMMU.
>>
>> Since this made the synth part of the driver non-functional on such systems
>> let's effectively revert that commit.
> 
> Let's keep (or re-add after this revert) the simplification with
> __synth_free_pages().  Other than that I have no objection to this
> change.

Will keep the simplification via __synth_free_pages() function in a respin.

> thanks,
> 
> Takashi

Thanks,
Maciej