[alsa-devel] [PATCH]: x86_64, audio: Fix system panic when DMA > 40 bits
travis at sgi.com
Thu May 2 20:59:28 CEST 2013
On 5/2/2013 11:20 AM, Stephen Warren wrote:
> On 05/02/2013 12:20 AM, David Henningsson wrote:
>> On 05/01/2013 09:04 PM, Mike Travis wrote:
>>> The audio driver mistakenly allows 64 bit addresses to be created for
>>> the audio driver on Nvidia GPUs. Unfortunately, the hardware normally
>>> only supports up to 40 bits of DMA. This can cause system panics as
>>> well as misdirected data when the address is > 40 bits as the upper
>>> part the address is truncated.
>> Thanks for this patch. Stephen Warren, is this something you can
>> confirm/deny, and do you know what range of hardware this actually
>> applies to?
> It's certainly plausible that the GPU's internal physical addresses are
> less than a full 64-bits, and this probably affects PCI accesses too.
I haven't noticed any other problems with MMIOH accesses. The
problem of DMA32 addresses certainly affects us though audio is
not a high priority on UV(*) except in specific applications (like
Media Servers, etc.] Accesses to the GPU and GPGPU are much more
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