On Mon, Nov 21, 2016 at 04:47:59PM -0500, Mark Hounschell wrote:
OK, I did get this message before the reported BUG message.
gpiohsd gpiohsd: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0xffffffffffee8000] [size=8192 bytes]
But I've verified that the dma_addr_t that I get for the alloc, and
also use for the free is 0x00000000ffee8000 in this case? Is device
"address=0xffffffffffee8000" in that message a bug in the message or
do we have a sign extended address problem? It seems strange to me,
I've never seen a dma_addr_t given, when using the iommu, that
high. In the past I've seen them as usually 0x00xxxxxx?
I have also verified that simply changing from
pci_alloc/free_consistent to the newer DMA API fixes my issue and I
get no such messages.
Yes, this looks like a sign-extension bug somewhere. But its not in the
amd-iommu driver, because dma-debug also sees it. And from what I can
tell the dma-api interface seems to be fine. It consistently uses
dma_addr_t to pass these values around.
Where can I find the source of the failing code? I need exactly the code
version that triggers the problem.