On Mon, 21 Jan 2013, Felipe Balbi wrote:

On Mon, Jan 21, 2013 at 05:16:06PM +0000, Arnd Bergmann wrote:

quoted

In linux-3.8-rc1 it became possible to build the imx and
mvebu platforms together in a single kernel, which clashes
in the ehci driver.

Manjunath Goudar is already working on a patch to convert
both the imx and the mvebu glue drivers (along with all
the other ARM specific ones) to the new probing method,
but that will be too late to fix v3.8. This patch instead
adds yet another hack like the existing ones to allow
the ehci driver to load both back-ends.

Pardon me for being confused.  Is this about imx and mvebu (as 
mentioned here) or about orion and mxc (as described in the patch 
title, the error messages below, and the patch itself)?

quoted

Without this patch, building allyesconfig results in:

drivers/usb/host/ehci-hcd.c:1285:0: error: "PLATFORM_DRIVER" redefined
drivers/usb/host/ehci-hcd.c:1255:0: note: this is the location of the previous definition
In file included from drivers/usb/host/ehci-hcd.c:1254:0:
drivers/usb/host/ehci-mxc.c:280:31: warning: 'ehci_mxc_driver' defined but not used

Was the point here to fix the build error or to allow the two drivers
to coexist?  The first would be eaiser than the second.

quoted

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb at vger.kernel.org
Cc: Manjunath Goudar <redacted>
Cc: Shawn Guo <redacted>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jason Cooper <redacted>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <redacted>

NAK, should be converted to the new usage of ehci library driver. Alan
Stern already implemented for a few drivers, help is very welcome.

Arnd, please take a look at

	http://marc.info/?l=linux-usb&m=135843716515529&w=2

I can't test it easily, not being set up for cross compilation.  I'm 
waiting to hear from anybody whether it works before submitting it.
(There's also a report of memory corruption involving a similar patch 
for ehci-omap; it hasn't been tracked down yet.)

Alan Stern