On 11/01/17 16:03, Nikita Yushchenko wrote:
>
>
> 11.01.2017 17:50, Robin Murphy пишет:
>> On 11/01/17 13:41, Nikita Yushchenko wrote:
Yes, I think that ought to work, although the __iommu_setup_dma_ops()
call will still want a real size reflecting the default mask
>>>
>>> I see
On 11/01/17 13:41, Nikita Yushchenko wrote:
>> Yes, I think that ought to work, although the __iommu_setup_dma_ops()
>> call will still want a real size reflecting the default mask
>
> I see iommu_dma_ops do not define set_dma_mask.
>
> So what if setup was done for size reflecting one mask and
> Yes, I think that ought to work, although the __iommu_setup_dma_ops()
> call will still want a real size reflecting the default mask
I see iommu_dma_ops do not define set_dma_mask.
So what if setup was done for size reflecting one mask and then driver
changes mask? Will things still operate
On 11/01/17 07:59, Nikita Yushchenko wrote:
>>> + /*
>>> +* we don't yet support buses that have a non-zero mapping.
>>> +* Let's hope we won't need it
>>> +*/
>>> + WARN_ON(dma_base != 0);
>>
>> I believe we now accomodate the bus remap bits on BCM2837 as a DMA
>> offset, so
>> +/*
>> + * we don't yet support buses that have a non-zero mapping.
>> + * Let's hope we won't need it
>> + */
>> +WARN_ON(dma_base != 0);
>
> I believe we now accomodate the bus remap bits on BCM2837 as a DMA
> offset, so unfortunately I think this is no longer true.
On 10/01/17 14:00, Nikita Yushchenko wrote:
> There are cases when device supports wide DMA addresses wider than
> device's connection supports.
>
> In this case driver sets DMA mask based on knowledge of device
> capabilities. That must succeed to allow drivers to initialize.
>
> However,
There are cases when device supports wide DMA addresses wider than
device's connection supports.
In this case driver sets DMA mask based on knowledge of device
capabilities. That must succeed to allow drivers to initialize.
However, swiotlb or iommu still need knowledge about actual device
