[PATCH v2 2/2] USB: doc: Binding document for ehci-platform driver

On Wednesday 24 October 2012 14:04:12 Alan Stern wrote:

On Wed, 24 Oct 2012, Florian Fainelli wrote:

quoted

As long as no one enables both ehci-platform and ehci-ppc-of at the same time
there is no problem. ehci-ppc-of should be removed in favor of ehci-platform
and make sure that the specific quirk in ehci-ppc-of also gets ported, other 
that I see no issue using "usb-ehci" as the least detailed compatible property
name.

Suppose a DT board file is created for a oontroller which ehci-platform
can't handle.  Then by your proposal, the board file shouldn't have
"usb-ehci" in its compatible property.

Now later on, suppose ehci-platform is enhanced so that it can manage
that controller.  It's too late to update the board file because the
information has already been written to various firmwares.  The
enhanced ehci-platform would have to include a special entry to match
the controller.

In any case you are supposed to use a compatible property which describes
as much as possible your hardware, and this one should have the precedence
if a special treatment is required, so I see no problem with this approach.

Since this reasoning applies every time ehci-platform is updated, it 
seems reasonable to use the same approach right from the beginning.

Alan Stern

-- 
Florian