[PATCH 3/5] documentation/iommu: update description of ARM System MMU binding

Timur Tabi timur at codeaurora.org
Fri Feb 28 12:07:31 EST 2014


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.




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