On Monday 07 April 2008, Felipe Balbi wrote: > I recall having some issues on 100mA devices. During enumeration some > current spikes a few mAs above 100mA were occuring and we couldn't > enumerate the device due to vbus_err interrupt. Yeah, I think the Mentor core is unduly sensitive to voltage fluctuation during enumeration. There's supposed to be about 100 msec before VBUS must stabilize ... but the silicon doesn't seem to accept routine instabilities in that period, and then reports inappropriate VBUS errors. > If you check drivers/usb/musb/tusb6010.c you'll see that we've > implemented a retry condition for those cases. The same retry can > be found in musb_core.c The DaVinci support needed the same kind of logic. All in all this is painful stuff to sort out, and it seems that each platform rediscovers it. It would be better if the silicon itself weren't fighting back so hard... - Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
