Thanks a lot Dennis . That was quite an insight. Actually we have placed that 100k resistor. Nowdays, the board is showing less of those kernel crashes. On Jan 23, 2014 11:50 PM, "Dennis Ferguson" <[email protected]> wrote:
> Hello, > > If you are still having the problem try to boot the kernel without the > console connected but with a jumper connecting UART0_RX to DGND on the > console port (that's pins 1 and 4 on the 6-pin console connector, if you > have one). > > If you leave the console uart receive pin (or any of the other uarts, I > think) unconnected and unterminated it will pick up noise, and the stream > of noise will find bugs in the kernel terminal driver and cause crashes. > Revision A5A of the BBB board got a 100k pull-down resistor attached to the > UART0_RX pin to prevent the noise (I assume), if your board hasn't got a > similar pull-down or pull-up you can have the difficulty you see. In fact, > even if your clone board includes the 100k resistor like a real BBB you may > have problems with this. I have two revision A5C BBB boards which also > cause kernel crashes in the serial driver when no console cable is > attached, though I have a handful of other boards which run reliably that > way, so I think the 100k value is marginal at fixing this on a real BBB. > Decreasing the resistance fixes these. Even if your clone board includes > the 100k pull-down the differences in board layout or construction may make > the 100k value less effective than on a real BBB (where it seems to just > barely work) so you may need to use a smaller value. > > Dennis Ferguson > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/1rbO7JGhppw/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- 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.
