Re: [linux-usb-devel] [PATCH] : Allow embedded developers USB options normally reserved for OTG

[Bryan Wu]

On Jan 3, 2008 11:43 AM, David Brownell <david-b@xxxxxxxxxxx> wrote:
> On Wednesday 02 January 2008, Robin Getz wrote:
> > On Wed 2 Jan 2008 13:47, David Brownell pondered:
> > > On Wednesday 02 January 2008, Robin Getz wrote:
> > > > From: Robin Getz <rgetz@xxxxxxxxxxxxxxxxxxxx>
> > > >
> > > > Allow embedded developers to turn support for USB Hubs off even if
> > > > they have a full root hub. This saves the overhead (RAM and Flash size).
> > >
> > > ISTR that it won't save very much code though ... the Linux USB
> > > stack structures all its enumeration logic around hubs.
> >
> > Today, there is an USB (Host), USB_GADGET and USB_OTG (which depends on USB &&
> > USB_GADGET).
> >
> > This just enables cutting more code out, with out having to have USB_GADGET &
> > USB_OTG enabled. When I checked - that is where most of the savings came
> > from.
>
> Right.  I'm not objecting to this at all.  Just pointing
> out that usbcore will still end up including quite a lot
> of hub functionality, because there's still going to be
> a root hub in the system and a khubd managing it.
>
> This patch might be improved slightly -- in ways that, as I
> understand things, could save some RAM on Blackfin! -- by
> having the BLACKLIST_HUB option get rid of the transaction
> translator support (changing C code not just Kconfig).
> It's pretty minimal, but won't be used...
>
> Also, as you point out, it's no longer OTG specific, so
> renaming the option would improve clarity.   Maybe to
> something along the lines of USB_HOST_NO_EXTERNAL_HUBS.
> No big deal, at least now.
>

Thanks, that's the point.
Maybe Robin can choose a good name of this option.
I am just very happy that when plug-in an external hubs or something
like that will not make our system hangs, -:)))

B.T.W, 2 questions about the MUSB driver:
1. What's the plan for mainline merge of the whole MUSB driver? maybe
I can cleanup current Blackfin ports to you guys.
2. Do you remember the PING issue I reported in OMAP list? How do you
think of that?

Best Regards,
-Bryan Wu
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/