Just an FYI... We are currently working on a project using Rev C BBB and RCN 3.13.11-bone12 kernel. We had been experiencing random reboots. Sometimes multiple times per day and sometimes once per day, mostly at night. We determined that the reboots were only occuring when the BBB was being powered only from the 5VDC connector. We never saw a reboot when the BBB was either powered from, or just connected to, the USB OTG port.
One of our engineers suggested that it might be a noise issue on the USB OTG port and the way that the TPS65217C PMIC works in the system. The way he explained it to me is that the PMIC is set up to default to the USB OTG port for power. If you leave the USB OTG port open, or floating, while powered from the 5VDC connector and then get noise on the USB OTG port then the PMIC will attempt to switch to USB OTG port and finding that there is no voltage there the system reboots. What we have done to solve the problem so far: I made a pigtail cable for the USB OTG port that simply ties the shield, ground and 5VDC together. There is no 5VDC on the USB OTG port when not connected to a host machine. Not a great final solution but it did prove the theory. With the pigtail installed we never get reboots, it's been tested on several BBBs now and is very consistent. So, reboots regularly without the pigtail and never with the pigtail installed. One other thing to note... On the schematic there are 4.7uF caps from both the USB OTG and 5VDC lines to ground. We were thinking that this could allow some relatively high frequency noise to pass to the PMIC. I don't know what the response time, that would cause a switch over, is on the PMIC. It's possible that something on the order of a .01uF - .1uF cap from the USB OTG 5VDC line to ground might also solve the problem. This has not been tested yet however. Hope this helps... On Thursday, October 30, 2014 4:50:43 AM UTC-5, Ives van der Flaas wrote: > > I'm running Robert C Nelson's latest 3.17 kernel (3.17.1-bone4) because I > need the new TI musb babble recovery code. It seems however that I'm having > some strange instability on my BBB. After somewhere between 10 and 24 > hours, the device seems to reset suddenly and without warning. There's no > kernel panic as far as I can see (no kernel.panic time-out in my sysctl > either) and nothing in the dmesg or kern log files. It suddenly resets. > > On the serial console, using my own FTDI cable, I was running "watch", and > when I returned the next day the program wasn't refreshing as it should > have been. I pressed enter and immediately a login prompt appeared. Uptime > was also way shorter than it should have been. > > Any clues on what might cause this? This seems a bit like a power supply > issue, but I've been running the same BBB for weeks using the same power > supply on a 3.8.13 kernel and that's always worked fine, while on this > kernel it can't even last a day. > > Thanks, > Ives > -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
