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To: Alexey Kardashevskiy <aik@ozlabs.ru>, linuxppc-dev@lists.ozlabs.org
From: Michael Ellerman <mpe@ellerman.id.au>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>, stable@vger.kernel.org.#.4.2+,
 Paul Mackerras <paulus@samba.org>
Subject: Re: [kernel,
 v2] powerpc/ioda: Set "read" permission when "write" is set
Message-Id: <20160219121328.EA947140B04@ozlabs.org>
Date: Fri, 19 Feb 2016 23:13:28 +1100 (AEDT)
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On Wed, 2016-17-02 at 07:26:31 UTC, Alexey Kardashevskiy wrote:
> Quite often drivers set only "write" permission assuming that this
> includes "read" permission as well and this works on plenty platforms.
> However IODA2 is strict about this and produces an EEH when "read"
> permission is not and reading happens.
> 
> This adds a workaround in IODA code to always add the "read" bit when
> the "write" bit is set.
> 
> This fixes breakage introduced in
> 10b35b2b74 powerpc/powernv: Do not set "read" flag if direction==DMA_NONE
> 
> Cc: stable@vger.kernel.org # 4.2+
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/6ecad912a0073c768db1491c27

cheers