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 common.