On Tue, 28 Sep 2004, David Brownell wrote: > > But hci-pci.c calls the driver's reset() in usb_hcd_pci_probe() -- how > > does OHCI avoid doing that reset? > > And that reset() method may be a bit misnamed. > The "reset" is just to get it into a known state, which > doesn't need to involve chip or USB reset. I don't > think either OHCI nor EHCI will do a USB reset...
UHCI does. Of course, the reset could be removed. Or better yet, issued only if one of the critical error bits is set in the Status register. > > Well, USB selective suspend now supports putting devices into the USB > > suspend state. It could also support turning off Vbus power entirely > > (without destroying the struct usb_device -- a true power-off selective > > suspend). > > No, that's a nonsense state for USB ... unless someone creates lots > of infrastructure to remember the devices that were present. That > got ripped out of usb-storage (on request from Linus, ISTR)... The problem is, we have to support it for STD (and maybe STR too) if there's no suspend power available when the system is off. Otherwise all the USB disk drives will vanish when the system resumes. That's going to be particularly bothersome for people who keep their root fs on a USB drive... :-) Alan Stern ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
