Re: [PATCH V3] pci: exynos: split into two parts such as Synopsys part and Exynos part

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi Arnd,

On Thursday 26 September 2013 03:21 PM, Arnd Bergmann wrote:
> On Thursday 26 September 2013, Kishon Vijay Abraham I wrote:
>> On Wednesday 25 September 2013 02:53 AM, Arnd Bergmann wrote:
>>> On Monday 23 September 2013, Kishon Vijay Abraham I wrote:
>>>> Btw if we hadn't programmed inbound translation table, the address will go
>>>> untranslated (according to the data book). I guess that's how it was working
>>>> for Jingoo Han.
>>>>
>>>> **
>>>> 3.10.4
>>>> Inbound iATU Operation
>>>>
>>>> When there is no match, then the address is untranslated
>>>> **
>>>>
>>>
>>> Well, that should work just as well, since you have a 1:1 translation anyway.
>>> Do you get the same error without the translation?
>>
>> Yes. I get the same non-fatal error interrupt in RC.
> 
> Ok, then I guess the translation is actually not at fault here but something
> else. I would recommend looking at the IOMMU as the potential culprit. Maybe
> having it disabled means that no DMA is going through, rather than all DMA
> going through untranslated. Another possibility is that the IOMMU is set up
> so that when disabled, it maps DMA address 0 to the start of RAM, rather
> than identity mapping DMA address 0x80000000 there. If that's the case,
> you either have to use the IOMMU, or set up the mapping in the root
> complex to revert it.

Thanks for your inputs. I'll check if that's the problem.

Thanks
Kishon