Thank you for a very informative reply ! Btw, I could not find a link to
usb2.html from www.linux-usb.org main page..
best
Vladimir Dergachev
On Mon, 15 Apr 2002, David Brownell wrote:
> > Is there some webpage I read it to find out the status of USB 2.0 support
> > in Linux ? (In particular the "highspeed mode" or whatever 480mbit/sec is
> > called).
> >
> > If not, could some enlighten me ?
>
> No webpage so far ... just try it out! Meanwhile:
>
> linux/Documentation/usb/ehci.txt ... in 2.4.19-pre6 and 2.5.8
>
> http://www.linux-usb.org/FAQ.html#gs6 ... about USB 2.0
>
> Short version of the story is
>
> USB 2.0 == USB 1.1
> + "high speed" (480 mbit/sec) busses and hubs
> + certification (two new logos; "highspeed" is two colors)
>
> The highspeed controller standard is called EHCI, and has Linux support.
> The USB 2.0 support includes hub and other usbcore updates, as well
> as the "ehci-hcd" driver for those highspeed controllers.
>
> The 2.5.8 "ehci-hcd" version is the most functional, and should work with
> EHCI implementions from NEC, Intel, Philips, VIA, and maybe more.
> It supports all four types of high speed transfers (control, bulk, interrupt,
> and isochronous). I'll update the 2.4 version to match it at some point.
> Currently the 2.4 driver is older: only NEC, no isochronous transfers.
>
> The "split transaction" support through high speed hubs is only partially
> functional so far though. Control and bulk transfers work through them,
> at least until certain kinds of errors happen. The hub driver doesn't yet
> know how to recover from those kinds of transaction translator error.
>
> Also, there is no support yet for split periodic transactions; it'll be easier
> for interrupt transfers (except scheduling) since split iso involves a new
> way to talk to EHCI implementations. (That means: don't hook up USB 1.1
> webcams, keyboards, mice, etc. to highspeed hubs, they'll enumerate
> but you won't be able to use them otherwise.)
>
> Linux USB 2.0 support seems to work pretty well for the usb-storage
> devices that now exist (modulo some slowdown from the usb-storage
> driver not queuing requests). That's all that most folk have so far, but
> highspeed scanners and printers ought to be in the works too.
>
> On the "develop a highspeed USB device" side, Cypress EZ-USB FX2
> plays nicely with Linux. I'm also looking forward to the new PCI based
> controller upcoming from NetChip ... that'll be practical to use in many
> embedded "Linux device" configurations! :)
>
> - Dave
>
>
>
>
>
>
> _______________________________________________
> [EMAIL PROTECTED]
> To unsubscribe, use the last form field at:
> https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
>
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
