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From: timur@codeaurora.org (Timur Tabi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/5] documentation/iommu: update description of ARM System MMU binding
Date: Fri, 28 Feb 2014 11:07:31 -0600	[thread overview]
Message-ID: <5310C253.40804@codeaurora.org> (raw)
In-Reply-To: <20140228162114.GA30996@mudshark.cambridge.arm.com>

On 02/28/2014 10:21 AM, Will Deacon wrote:
>>> > >+- calxeda,smmu-secure-config-access : Enable proper handling of buggy
>>> > >+                  implementations that always use secure access to
>>> > >+                  SMMU configuration registers. In this case non-secure
>>> > >+                 aliases of secure registers have to be used during
>>> > >+                 SMMU configuration.
>> >
>> >I'm confused.  Why does this property have a "calxeda" prefix?  How is
>> >it a Calxeda-specific property?

> Because they wired up their SMMU backwards. It's basically an
> implementation-specific erratum workaround.

Hmmmm....

Other than making the same wiring mistake, is there any reason any other 
ARM chip would need this property set?

The reason I ask is that it's kinda weird (well, to me at least) that we 
have an property named for a specific SoC, but the implementation and 
documentation tries so hard to hide that fact.  I would think that the 
binding document would provide some explanation as to why the property 
has a "calxeda" prefix.

  reply	other threads:[~2014-02-28 17:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-21 17:16 [PATCH 0/5] iommu/arm-smmu: updates for 3.15 Will Deacon
2014-02-21 17:16 ` [PATCH 1/5] iommu/arm-smmu: set MAX_MASTER_STREAMIDS to MAX_PHANDLE_ARGS Will Deacon
2014-02-21 17:16 ` [PATCH 2/5] iommu/arm-smmu: support buggy implementations with secure cfg accesses Will Deacon
2014-02-21 17:16 ` [PATCH 3/5] documentation/iommu: update description of ARM System MMU binding Will Deacon
2014-02-21 18:57   ` Sergei Shtylyov
2014-02-28 16:17   ` Timur Tabi
2014-02-28 16:21     ` Will Deacon
2014-02-28 17:07       ` Timur Tabi [this message]
2014-03-04 10:08         ` Will Deacon
2014-03-04 13:20           ` Timur Tabi
2014-02-21 17:16 ` [PATCH 4/5] iommu/arm-smmu: clean up use of `flags' in page table handling code Will Deacon
2014-02-21 17:16 ` [PATCH 5/5] iommu/arm-smmu: provide option to dsb macro when publishing tables Will Deacon

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