Re: [RFC v1 PATCH 1/2] of/pci: add of_pci_dma_configure() update dma configuration

[Murali Karicheri <m-karicheri2@ti.com>]

On 12/23/2014 05:42 PM, Arnd Bergmann wrote:
> On Tuesday 23 December 2014 12:42:05 Murali Karicheri wrote:
>>> here.
>>
>> Arnd,
>>
>> I guess so. Besides we need to keep the default coherent dma mask to
>> 32bit 0xffffffffull as well to work on Keystone and also in sync with
>> current defaults used in pci_device_add() so that we don't break this
>> behavior.
>>
>> Here is the summary of changes need to make on top of my existing patch.
>>
>> 1. of_dma_configure() - change size = dev->coherent_dma_mask to size =
>> dev->coherent_dma_mask + 1. This is a new patch to fix existing code.
>
> ok
>
>> 2. Do the above change to of_pci_dma_configure() as well.
>
> ok
>
>> 3. in arch_setup_dma_ops() update the DMA mask to min((*dev->dma_mask),
>> dma_base + size - 1) as
>>
>>
>> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
>> index c17f6a9..88b4769 100644
>> --- a/arch/arm/mm/dma-mapping.c
>> +++ b/arch/arm/mm/dma-mapping.c
>> @@ -2053,8 +2053,13 @@ void arch_setup_dma_ops(struct device *dev, u64
>> dma_base, u64 size,
>>    {
>>           struct dma_map_ops *dma_ops;
>>
>> +
>> +       *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
>>
>> I have tested this on keystone and it works fine with rootfs on PCI SATA
>> harddisk. I will be doing more tests with this change. If you are in
>> agreement with the above changes, I will re-spin the patch to accomodate
>> them and send v1 of the same.
>
> Ok, sounds good. I noticed that you did not put Russell into the Cc list
> for the emails. Please do so when you send it again, as he may have some
> additional comments.
Ok. Will do.

Murali
>
> 	Arnd


-- 
Murali Karicheri
Linux Kernel, Texas Instruments