[PATCH] of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc

[Michael Ellerman]

Rob Herring <robh at kernel.org> writes:
> On Sun, 26 Jan 2020 22:52:47 +1100, Michael Ellerman wrote:
>> There's an OF helper called of_dma_is_coherent(), which checks if a
>> device has a "dma-coherent" property to see if the device is coherent
>> for DMA.
>> 
>> But on some platforms devices are coherent by default, and on some
>> platforms it's not possible to update existing device trees to add the
>> "dma-coherent" property.
>> 
>> So add a Kconfig symbol to allow arch code to tell
>> of_dma_is_coherent() that devices are coherent by default, regardless
>> of the presence of the property.
>> 
>> Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
>> when the system has a coherent cache.
>> 
>> Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
>> Cc: stable at vger.kernel.org # v3.16+
>> Reported-by: Christian Zigotzky <chzigotzky at xenosoft.de>
>> Tested-by: Christian Zigotzky <chzigotzky at xenosoft.de>
>> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
>> ---
>>  arch/powerpc/Kconfig | 1 +
>>  drivers/of/Kconfig   | 4 ++++
>>  drivers/of/address.c | 6 +++++-
>>  3 files changed, 10 insertions(+), 1 deletion(-)
>> 
>
> Applied, thanks.

Thanks.

cheers