Mis?use of aliases

Mitch Bradley wmb at firmworks.com
Sat Jul 14 15:30:42 EST 2012


> I'm not sure this is really a good use of aliases. UARTs use aliases
> because it is important that the UART number to tty number is known and
> fixed.

This brings up an issue that I've been meaning to comment on.

The use of phandle-valued properties in the aliases node causes real OFW
implementations some amount of heartburn.  The Open Firmware standard
says that the properties in /aliases are string-valued.  That's
important, because aliases are shorthand for fragments of full device
specifiers (pathnames that can include arguments to nodes).  Phandles
can point to nodes, but can't be relative, and can't encode
per-node-component arguments.

For binding a Linux unit number to a device node, I would prefer to
decorate the node with a property like "linux,unit#", instead of
breaking the standard semantics of /aliases.

Mitch


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