[alsa-devel] [PATCH] ALSA: hda - allow 40 bit DMA mask for NVidia devices

[Ard Biesheuvel]

On 18 October 2016 at 11:25, Takashi Iwai <tiwai at suse.de> wrote:
> On Mon, 17 Oct 2016 18:23:59 +0200,
> Ard Biesheuvel wrote:
>>
>> Commit 49d9e77e72cf ("ALSA: hda - Fix system panic when DMA > 40 bits
>> for Nvidia audio controllers") simply disabled any DMA exceeding 32
>> bits for NVidia devices, even though they are capable of performing
>> DMA up to 40 bits. On some architectures (such as arm64), system memory
>> is not guaranteed to be 32-bit addressable by PCI devices, and so this
>> change prevents NVidia devices from working on platforms such as AMD
>> Seattle.
>>
>> Since the original commit already mentioned that up to 40 bits of DMA
>> is supported, and given that the code has been updated in the meantime
>> to support a 40 bit DMA mask on other devices, revert commit 49d9e77e72cf
>> and explicitly set the DMA mask to 40 bits for NVidia devices.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>
> Thanks, applied.  Since this seems causing a real problem, I added Cc
> to stable.
>

Thanks!