On Tue, 9 Jun 2009, Matthew Garrett wrote: > On Mon, Jun 08, 2009 at 07:47:06PM -0400, Alan Stern wrote: > > On Mon, 8 Jun 2009, Matthew Garrett wrote: > > > > > If I indicate it needs a reset-resume then it doesn't seem to actually > > > be reset unless I add the needs_binding option in the reset_resume > > > callback, which strikes me as being absolutely the wrong thing to do. > > > > It sure is. > > > > I don't understand why you don't get a reset. In driver.c, > > usb_resume_device() includes this code: > > > > if (udev->quirks & USB_QUIRK_RESET_RESUME) > > udev->reset_resume = 1; > > > > That's why setting the quirk bit in udev should be all you need to do. > > The needs_binding option only seems to be set in the case where > USB_QUIRK_RESET_RESUME is present but there's no reset_resume callback > in the driver? I don't have enough experience of the USB core to know > what that's actually doing. needs_binding is private to usbcore; it shouldn't be used by drivers. It gets set when usbcore has to unbind a driver because the driver doesn't support suspend, resume, or reset_resume, and then later on it causes usbcore to probe for new drivers after the device has been resumed or reset. > > > When system suspend takes place it reboots itself and appears as a > > > different USB ID, so there's no hope of restoring state. > > > > In theory, the behavior during a system suspend should be the same as > > the behavior during an autosuspend. Which means that after an > > autoresume, the device should show up with a different USB ID and so > > the reset would fail. But that's probably not what's really happening. > > The card comes up in a dumb state and then gets fed 16MB worth of armel > ELF object which causes it to reboot into a more useful form. It stays > in that state until the power plane is entirely cut, which happens in > system suspend but not in autosuspend. It shouldn't happen in system suspend. Why doesn't the system provide suspend current to the USB bus? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
