On 11/10/2015 3:38 AM, Arnd Bergmann wrote:
> No, as Timur found, the driver is correct and it intentionally
sets the 32-bit mask, and that is guaranteed to work on all sane
hardware. Don't change the driver but find a better platform for
your workload, or talk to the people that are responsible for
the platform and get them to fix it.
Platform does have an IOMMU. No issues there. I am trying to clean out
the patch pipe I have in order to get this card working with and without
IOMMU.
If the platform also doesn't have an IOMMU, you can probably work
around it by setting up the dma-ranges property of the PCI host
to map the low PCI addresses to the start of RAM. This will also
require changes in the bootloader to set up the PCI outbound translation,
and it will require implementing the DMA offset on ARM64, which I was
hoping to avoid.
From the email thread, it looks like this was introduced to support
some legacy card that has 64 bit addressing limitations and is being
carried around ("rotted") since then.
I'm the second guy after the powerpc architecture complaining about the
very same issue. Any red flags?
I can't change the address map for PCIe. SBSA requires all inbound PCIe
addresses to be non-translated.
I'll just have to stick with IOMMU for this card.
--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project
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