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Message-ID: <87k157gb8u.fsf@mpe.ellerman.id.au>
Date: Fri, 31 Jan 2020 21:40:17 +1100
From: Michael Ellerman <mpe@...erman.id.au>
To: Rob Herring <robh@...nel.org>
Cc: robh+dt@...nel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, hch@....de, ulf.hansson@...aro.org,
chzigotzky@...osoft.de, linuxppc-dev@...abs.org
Subject: Re: [PATCH] of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc
Rob Herring <robh@...nel.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@...r.kernel.org # v3.16+
>> Reported-by: Christian Zigotzky <chzigotzky@...osoft.de>
>> Tested-by: Christian Zigotzky <chzigotzky@...osoft.de>
>> Signed-off-by: Michael Ellerman <mpe@...erman.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
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