60 MHz clock on Beagleboard REV C4 problem

Searching through the BB schematics I found that this clock can be seen on resistor number 53. Okay, I found that clock using my oscilloscope and it looks perfectly healthy. But when I plug in my web-camera, or USB high speed hub into my EHCI port, clock disappears. And I’m getting message that the device is busy:

usecount = 2
ehci-omap ehci-omap.0: init_60m_fclk set parentfailed error:-16
usecount = 2
ehci-omap ehci-omap.0: init_60m_fclk set parentfailed error:-16
usecount = 4
ehci-omap ehci-omap.0: xclk60mhsp1_ck set parentfailed error:-16
usecount = 4
ehci-omap ehci-omap.0: xclk60mhsp2_ck set parentfailed error:-16

I found out that in order that function clk_set_parent() properly works, variable usecount (number of instances that use this clock source particularly) should be equal to zero. But it equals to 2, and then to 4.

What else could be using this clock source on BB? Does anyone have that information?

This problem occurred after some malfunction of the BB. Namely, I burned it by exposing it to the voltage of 12V. It was an accident. After that I realized that the U1 chip on BB (TPS2141) is actually burned. I replace it, but now I am facing this error. My OTG also doesn’t work.

I’m working on it, to get it in shape again, but I’m asking here just in case that someone have had similar problems with clock source unavailability.

RMA request will save you

2012/10/31 Krcevina <vojislav.mokric@gmail.com>

Yeah, that would be the easy way around… Still, I want to try it by myself. Everything is pretty much well documented, so why not try it.

среда, 31. октобар 2012. 11.28.24 UTC+1, lisarden је написао/ла:

unfortunately TI documentation does not cover the 12V burnout

2012/10/31 Krcevina <vojislav.mokric@gmail.com>

You apply 12V and all bets are off as to what can get damaged. Processors can rarely be repaired. Only replaced.

Gerald

Yeah lisarden, that is true. At least I want to try to fix it somehow on my own. Firstly, because I need to finish my master-thesis as soon as possible, and secondly, BB isn’t mine :slight_smile:

I am from Serbia. Do you happen to know, in case that I want to order new BB rev C4 (C5) for myself, to which distributor in Europe should I refer to?

Thanks!

Gerald, but my BB is booting quite well. It is possible to read from USB 2.0 stick. EHCI port isn’t complaining about that. But it complains to USB WEB camera and USB high speed port… The thing that bothers me now is this 60 MHz clock. I found this patch, but it isn’t helping…http://lists.infradead.org/pipermail/linux-arm-kernel/2012-June/105465.html

Your call. But, I have never heard of the 60MHz clock going away as you describe.

As to the distributor, it needs to go back to the one it was purchased from and they should be able to provide a replacement fairly quickly, depending on where it is located. You will need to get the RMA approved before sending it anywhere.

One thing to note. The port is full speed only. To support Hi or low speed devices, you need a hub in between.

Gerald

Thanks Gerald. I will look and see from where it was ordered… Nevertheless I’m buying one for myself, and that’s why I asked which distributor is the most pleasant to work with. I tried to order BB REV C5 from Farnell.uk but they are very hard to cooperate with…

Yes, I know about the hub of course. But the problem is that my hub affects in such a way that he looses his external 60 MHz clock. Funny… Another thing to add is that USB OTG isn’t working either, but fortunately I don’t need him…