Messages in this thread | | | Date | Thu, 3 Jan 2008 12:40:14 +0800 | From | "Bryan Wu" <> | Subject | Re: [linux-usb-devel] [PATCH] : Allow embedded developers USB options normally reserved for OTG |
| |
On Jan 3, 2008 11:43 AM, David Brownell <david-b@pacbell.net> 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@blackfin.uclinux.org> > > > > > > > > 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
| |