Hi, On Fri, Aug 10, 2012 at 01:32:00AM +0000, Chen Peter-B29397 wrote: > > > > > looks correct. Now that struct usb_otg should handle all otg details, it > > makes sense to put the state there. The problem is that a few of the > > states aren't really OTG specific. I think the only two otg-specific > > states are A_DEVICE and B_HOST... > > > According to USB_OTG_and_EH_2-0-final_plus_errata_and_ecn_20110714 - final.pdf > Chapter7.1, 7,2. The states at enum usb_otg_state are all OTG state. > > If you think others (except for A_DEVICE and B_HOST) are not otg-specific states, > then what are they? granted, they were defined on the OTG spec, but if you think about them, every peripheral usb controller starts on B_IDLE state. The OTG spec also says that any device can start SRP and any host can reply to that, not only OTG-capable devices; which means that B_SRP_INIT also applies to any device. B_PERIPHERAL applies to any device which gets enumerated. B_WAIT_ACON also applies to any device; it's that small timeframe where your device is ready and just waits for host. A_IDLE it's when your host is fully initialized but has no devices attached to it. A_WAIT_VRISE and A_WAIT_VFALL is applicable to any hosts which can control their charge pumps. A_WAIT_BCON is applicable to any host A_HOST is the normal operation of a host when it enumerated a device A_SUSPEND applies to any host. It's when it drives bus suspend signalling on the bus A_VBUS_ERR is that state when you just caught overcurrent. -- balbi
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