On 5/13/2020 8:26 AM, Andy Shevchenko wrote:

On Wed, May 13, 2020 at 08:08:07AM -0700, Florian Fainelli wrote:

quoted

On 5/13/2020 5:26 AM, Greg Kroah-Hartman wrote:

quoted

On Tue, May 12, 2020 at 11:00:15AM -0400, Al Cooper wrote:

quoted

Some BRCMSTB USB chips have an XHCI, EHCI and OHCI controller
on the same port where XHCI handles 3.0 devices, EHCI handles 2.0
devices and OHCI handles <2.0 devices. Currently the Makefile
has XHCI linking at the bottom which will result in the XHIC driver
initalizing after the EHCI and OHCI drivers and any installed 3.0
device will be seen as a 2.0 device. Moving the XHCI linking
above the EHCI and OHCI linking fixes the issue.

What happens if all of these are modules and they are loaded in a
different order?  This makefile change will not help with that, you need
to have logic in the code in order to properly coordinate this type of
mess, sorry.

I believe we should be using module soft dependencies to instruct the
module loaders to load the modules in the correct order, so something
like this would do (not tested) for xhci-plat-hcd.c:

MODULE_SOFTDEP("post: ehci-hcd ohci-hcd");

and I am not sure whether we need to add the opposite for ehci-hcd and
ohci-hcd:

MODULE_SOFTDEP("pre: xhci-plat-hcd");

JFYI: not all user space support this (alas, but that's current state of
affairs), OTOH I don't really care about those which do not support it
(Busybox).

I know that Gentoo's initramfs tool does not support it, however given
there are no symbols being cross referenced, I am not sure how to best
support this other than using these hints, and possibly making use of
device links too?
-- 
Florian