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. (* http://www.sgi.com/products/servers/uv/) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
