On 7/6/11, Robert Jarzmik <robert.jarzmik@xxxxxxx> wrote: > On 07/05/2011 03:08 PM, Dmitry Eremin-Solenikov wrote: >> Now as all drivers were converted to using gpio-vbus, drop gpio-pullup >> handling from pxa UDC drivers, thus simplifying them a bit. > > Is this patch compliant with USB 2 specification regarding maximum time > between pullup triggering and UDC ready to answer the "RESET" packet and > be assigned an address ? > > This is the sequence I'm worried about : > (1) The gpio-vbus is loaded > (2) The pxa27x_udc is loaded > (3) USB cable is plugged > => VBUS is sensed > (4) gpio-vbus pulls up the D+ (Dmitry, is that right ?) > (5) the host waits for UDC to settle (100 ms ?) > (5) set address packet(s) are sent from host to UDC > (6) UDC is not enabled, as no gadget is registered > => UDC doesn't answer > => usb host cannot assign it an address > (7) a gadget is loaded (g_ether for example) > => UDC is enabled, but too late > > Alan, Gregh, could you confirm point (5) about a maximum time between D+ > line activation and UDC duty to repond to "set address" packets, as well > as the consequence of point (6) where the usb device is rejected because > no address could be assigned ? > > Dmitry, could you confirm the the D+ pullup is done at point (4) ? No, I can't confirm this. IIUC, evrything happens in abit different way: (4) trancseiver notifies udc about VBUS sense (5) a gadget is loaded (g_ether for example) (6) gadget asks udc to enale pullup (7) udc tells gpio_vbus to enable pullup. etc... > > Cheers. > > -- > Robert > -- With best wishes Dmitry -- 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
