I wonder if the ethernet problems (link is down) has been resolved?

W dniu piątek, 13 stycznia 2012 13:18:04 UTC+1 użytkownik Gerald napisał:
>
> Thank you!
>  
> Gerald
>
>
>  
> On Fri, Jan 13, 2012 at 4:49 AM, Jorgen <[email protected] <javascript:>
> > wrote:
>
>> I shipped the board today. I expect the 'Beagle Hospital' ;-) will
>> receive it on Monday.
>>
>> On Jan 12, 3:20 pm, Gerald Coley <[email protected]> wrote:
>> > Yes, there may be a manufacturing defect. That is why we want the board
>> > back. We have shipped 4500 boards so far, on only have a few that show 
>> this
>> > issue, and none of them are in our possession. We may have something 
>> that
>> > we are missing in our production testing. In order to fix it, we have to
>> > figure out what it is. And based on what it is we can figure out how to
>> > test for it and resolve the issue.
>> >
>> > Gerald
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > On Thu, Jan 12, 2012 at 5:11 AM, Jorgen <[email protected]> wrote:
>> > > My fix, where I replaced R23 (10K) with 3.6K only worked for a short
>> > > while. The initial reset voltage was ~2.5V, but after perhaps half an
>> > > hour it fallen to 1.6V, and the Ethernet port was once again not
>> > > working. I then replaced the pull-up resistor with 340R, and measured
>> > > 3.1V for reset. This time I put a scope on the signal, and found that
>> > > the reset signal was toggling between ~3.1V and ~2.6V. I am pretty
>> > > sure that if I replaced R23 with 3.6K again, I would see the voltage
>> > > toggling between 3.3V and 1.6V (the average of these is pretty close
>> > > to the 2.5V I measured with a multimeter).
>> >
>> > > One explanation for this is that there may be a manufacturing defect
>> > > on the board, shorting the reset signal to another signal. Another
>> > > possibility is that the CPU is driving the reset signal from the
>> > > NRESET_INOUT pin, because it can't be the U16A buffer, which should
>> > > easily be able to drive the reset signal to ground, even with a 340
>> > > ohm pull to 3.3V.
>> >
>> > > I have sent full details, including a scope shot, to beagleboard RMA.
>> > > I will also be returning the board in a couple of days, so they can
>> > > take a look at it.
>> >
>> > > On Jan 12, 10:20 am, Jorgen <[email protected]> wrote:
>> > > > As I mentioned before, I found that on my board nRST to the PHY was
>> > > > only 1.4V. According to the LAN8710A datasheet, Vih(min) is also 
>> 1.4V,
>> > > > so it is not surprising that the PHY sometimes starts up, and
>> > > > sometimes doesn't, since there is no noise margin at all.
>> >
>> > > > It turns out that the reset signal is driven by an open-collector
>> > > > buffer U16A, with a 10K pull to VDD_3V3A. I measured the VDD_3V3A
>> > > > supply to be 3.3V. I replaced R23 with a 3.6K resistor, and now I
>> > > > measure 2.5V for nRST. The board is currently running, and I am 
>> going
>> > > > to leave it on for a couple of days to be sure that the ethernet 
>> does
>> > > > not shut down again.
>> >
>> > > > There must be an internal pull down on the reset pins on either the
>> > > > LAN8710A or the AM3359 (perhaps both), nothing else is connected to
>> > > > this net. There is no mention of an internal pull resistor in the
>> > > > LAN8719A DC specs. I haven't checked the 3359 datasheet.
>> >
>> > > > I would suggest that you check the nRST voltage on some more boards,
>> > > > if they all have marginal values, you should change the value of R23
>> > > > to something lower.
>> >
>> > > > On Jan 11, 5:45 pm, Jorgen <[email protected]> wrote:
>> >
>> > > > > I have had the board in our lab, and tried to measure if there 
>> were
>> > > > > any obvious problems. The only thing I found was that nRST is at 
>> about
>> > > > > 1.4V, so it looks like the reset signal is not being driven. The 
>> PHY
>> > > > > is also not sending link pulses, but doesn't necessarily need to 
>> be
>> > > > > because of the reset signal, the PHY coould be in powerdown mode. 
>> But
>> > > > > ss can be seen from the kernel message (PHY 0:00 not found) it is 
>> not
>> > > > > responding on the management interface, which definitely should 
>> not
>> > > > > happen unless the part is reset.
>> >
>> > > > > I'm going to try to solder a pullup on the reset signal, that 
>> should
>> > > > > help. But I won't have time until tomorrow. I'll let you know the
>> > > > > result.
>> >
>> > > > > On Jan 11, 5:22 pm, Jorgen <[email protected]> wrote:
>> >
>> > > > > > I'd rather not. I'm in Europe (Denmark), and I looked up the 
>> shipping
>> > > > > > cost of returning the board. It is quite a bit more than I paid 
>> for
>> > > > > > the board (incl. shipping) in the first place :-(
>> >
>> > > > > > On Jan 11, 5:11 pm, Gerald Coley <[email protected]> 
>> wrote:
>> >
>> > > > > > > I suggest you send it in under an RMA so we can look at it 
>> from an
>> > > > > > > electrical point of view.
>> >
>> > > > > > > Gerald
>> >
>> > > > > > > On Wed, Jan 11, 2012 at 10:06 AM, Jorgen <
>> [email protected]>
>> > > wrote:
>> > > > > > > > Well that was fast, the PHY is once again not responding.
>> >
>> > > > > > > > If I reboot the board (either soft or hard), I get a kernel
>> > > message:
>> > > > > > > > [   21.001710] PHY 0:00 not found
>> > > > > > > > See also:
>> >
>> > >http://groups.google.com/group/beagleboard/browse_thread/thread/a8413.
>> ..
>> >
>> > > > > > > > On Jan 11, 4:49 pm, Jorgen <[email protected]> wrote:
>> > > > > > > > > I have had problems with my ethernet port, as I have 
>> described
>> > > on
>> > > > > > > > > another thread.
>> >
>> > > > > > > > > I have replaced uImage with your uImage-beaglebone.bin, 
>> and so
>> > > far it
>> > > > > > > > > is working. But since it was an intermittent fault, it 
>> will
>> > > take a few
>> > > > > > > > > days before I know for sure whether your patch makes a
>> > > difference.
>> > > > > > > > > I'll leave the board running, and report back in a couple 
>> of
>> > > days.
>> >
>> > > > > > > > > On Jan 10, 11:27 pm, Jason Kridner <
>> [email protected]>
>> > > wrote:
>> >
>> > > > > > > > > > On Tue, Jan 10, 2012 at 8:25 AM, Bjoern Krombholz <
>> > > [email protected]>
>> > > > > > > > wrote:
>> > > > > > > > > > > Hi,
>> >
>> > > > > > > > > > > though I don't own a BeagleBone (yet) I noticed a lot 
>> of
>> > > issues being
>> > > > > > > > > > > reported regarding non working or faulty Ethernet 
>> ports.
>> >
>> > > > > > > > > > > We are building a AM3503/17 based boards which AFAIK 
>> use
>> > > the same
>> > > > > > > > Ethernet
>> > > > > > > > > > > block, we are also using the LAN8720A PHY which is 
>> nearly
>> > > identical
>> > > > > > > > to the
>> > > > > > > > > > > LAN8710A used on the Bone.
>> >
>> > > > > > > > > > > I remember seeing similar problems with our device.
>> > > Sometimes it just
>> > > > > > > > > > > worked, sometimes it didn't and often the link 
>> detection
>> > > was just
>> > > > > > > > extremely
>> > > > > > > > > > > unreliable.
>> >
>> > > > > > > > > > > I can't guarantee that my solution will work for the 
>> bone
>> > > problem,
>> > > > > > > > but I
>> > > > > > > > > > > think it's worth a try. The required change can be 
>> found at
>> > > > > > > > > > > <
>> >
>> > >
>> https://github.com/pironex/pia-linux-kernel/commit/bd65d378c5b152ea4b...>
>> > > > > > > > > > > (to get the patch, just add ".patch" to the URL.)
>> >
>> > > > > > > > > > > It simply disables the automatic "powerdown via link 
>> energy
>> > > > > > > > detection"
>> > > > > > > > > > > feature (which doesn't seem to work as expected) for 
>> the
>> > > PHY.
>> >
>> > > > > > > > > > Thanks for sharing!  I've applied this patch to the
>> > > BeagleBone kernel
>> > > > > > > > > > [1].  It would be great to collect some data points from
>> > > people seeing
>> > > > > > > > > > this issue.  I'm not currently reproducing it, but it 
>> could
>> > > be my
>> > > > > > > > > > network just has too much traffic.  Can folks seeing 
>> this
>> > > issue try
>> > > > > > > > > > out my pre-built kernel [2] by copying 
>> uImage-beaglebone.bin
>> > > as uImage
>> > > > > > > > > > into the FAT partition?
>> >
>> > > > > > > > > > [1]
>> >
>> > >http://groups.google.com/group/beagleboard/browse_thread/thread/776a4.
>> ..
>> > > > > > > > > > [2]
>> www.beagleboard.org/~share/beaglebone-debug-20120110/
>> >
>> > > > > > > > > > > Hope I could help
>> > > > > > > > > > > Björn
>> >
>> > > > > > > > > > > --
>> > > > > > > > > > >http://www.pironex.de
>> >
>> > > > > > > > --
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