Re: [PATCH] of: change fixup of dma-ranges size to error

From: Frank Rowand
Date: Mon Apr 10 2017 - 07:59:39 EST


On 04/10/17 04:48, Sricharan R wrote:
> Hi Frank,
>
> <snip..>
>
>>>> Can we get back to the basic premise of the proposed patch?
>>>>
>>>> The current code in of_dma_configure() contains a hack that allows the
>>>> dma-ranges property to specify a mask instead of a size. The binding
>>>> in the specification allows a size and does not allow a mask.
>>>>
>>>> The hack was added to account for one or more dts files that did not
>>>> follow the specification. In the mail list discussion of the hack
>>>> you said "Also, we need a WARN here so DTs get fixed."
>>>>
>>>> The hack was first present in Linux 4.1. The only in-tree dts that
>>>> incorrectly contained a mask instead of a size in dma-ranges was
>>>> arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
>>>>
>>>> That .dtsi was fixed by
>>>> commit c91cb9123cdd ("dtb: amd: Fix DMA ranges in device tree")
>>>> The fix was present in Linux 4.6, May 15, 2016.
>>>>
>>>> I would like to remove the hack. I think that enough time has
>>>> elapsed to allow this change.
>>>
>>> If we have no cases of what I'm concerned about, then removing it is
>>> fine. Is this a dependency for iommu series? Doesn't look like it to
>>> me.
>>
>> This patch is a replacement for patch 03/12 in the iommu series. I
>> think that patch 03/12 of the iommu series could be dropped and my
>> patch could be applied independently of the iommu series.
>>
>> There is likely a conflict between my patch and patch 06/12 of the
>> iommu series because in my patch the first line of the patch chunk
>> of drivers/of/device.c includes a line that is changed in 06/12
>> of the iommu series. If this is the case then the iommu series
>> should take precedence over my patch (and I should subsequently
>> fixup my patch).
>>
>
> Ok, for which i just posted a V11 [1] with patch 03/12 from
> V10 dropped.
>
> [1] https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1373638.html
>
> Regards,
> Sricharan
>

Thanks. I'll revisit this patch after the iommu series gets merged.

-Frank