On Thu, 28 Mar 2013, Arnd Bergmann wrote:

From: Manjunath Goudar <redacted>

Separate the  Qualcomm QSD/MSM on-chip host controller driver from
ehci-hcd host code so that it can be built as a separate driver module.
This work is part of enabling multi-platform kernels on ARM;
however, note that other changes are still needed before Qualcomm QSD/MSM
can be booted with a multi-platform kernel, which is not expected before
3.11.

With the infrastructure added by Alan Stern in patch 3e0232039
"USB: EHCI: prepare to make ehci-hcd a library module", we can
avoid this problem by turning a bus glue into a separate
module, as we do here for the msm bus glue.

This patch is good.  However the ehci-msm driver itself is not.  While
checking through the code, I was struck by the fact that it never calls
usb_add_hcd() or usb_remove_hcd().  Obviously the driver cannot work
properly.

In addition, it stores the PHY pointer in a global variable.  
(ehci-atmel does much the same thing for its clocks.)  This means the
driver cannot be used on a system having more than one EHCI controller.  
Maybe this doesn't matter, though.

Maybe somebody would like to fix and test it...

Alan Stern