The abstract from the TPS65217 datasheet to describe what is going on here:
The linear charger periodically applies a 10-mA current source to the BAT pin to check for the presence of a battery. This will cause the BAT terminal to float up to > 3 V which may interfere with AC removal detection and the ability to switch from AC to USB input. For this reason, it is not recommended to use both AC and USB inputs when the battery is absent. 2013/12/4 <[email protected]> > > On Tuesday, December 3, 2013 12:32:03 PM UTC-5, Lei Wang wrote: >> >> Follow your finding on the unexpected TPS65217C behavior, I patched the >> tps65217 driver with irq handling. The 3.2 kernel does not handle >> nNMI/PMIC_INT interrupt; the 3.8 kernel does. I placed printk in the >> interrupt handler and got the same result as yours. The PMIC_INT was issued >> every 2 seconds which is caused by the USBI flag in the TPS65217C interrupt >> register. >> >> > > This appears to be related to USB OTG. The VBUS, ID, and D+ pins on USB0 > are all generating 0.5 Hz signals. The signal on VBUS that the TPS65217C is > detecting may be OTG probing. > > This may not be the cause of the random reboots, but it's worth some > examination. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- LinkedIn - http://www.linkedin.com/in/maximpodbereznyy Company - http://www.linkedin.com/company/mentorel Facebook - https://www.facebook.com/mentorel.company -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
