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Message-ID: <20200128142646.GA17341@bogus>
Date: Tue, 28 Jan 2020 08:26:46 -0600
From: Rob Herring <robh@...nel.org>
To: Michael Ellerman <mpe@...erman.id.au>
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
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.
Rob
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