Hi Albin,
On Tue, Aug 25, 2009 at 4:37 AM, Albin Tonnerre albin.tonnerre@free-electrons.com wrote:
I guess you mean SBC35-A9G20?
I actually tried it with the patches for both boards (TNY & SBC35) and saw the same result.
Everything seems to work properly except the RTC. They use the same M41T94 part and the CS is the same on both boards (PA3). I can set the RTC using the "date" command and read back the value okay. However, when I power cycle the board, the value is getting corrupted at startup due to some erroneous SPI write.
I don't believe the code you submitted is causing this problem because the RTC is getting corrupted even if I compile out SPI and RTC support completely. I was just wondering if you have seen this problem on your board?
Yes, I also experience this issue.
Well, at least I'm not the only one. :)
I probed the CS line with an oscilloscope and I am definitely seeing it go low on U-Boot startup for a short time, but the clock line seems to be floating. I believe the activation of the CS at startup is causing junk data to be written to the RTC, which is corrupting it. Any idea why this might be happenning?
Currently, I don't really have any idea. Besides, it's going to be hard for me to debug this, as I don't have an oscilloscope at hand. Would you please try to run u-boot within a debugger to see where exactly the CS line is driven low?
I upgraded to the "next" branch and the problem seems to have gone away. I will continue to investigate the root cause of this and let you know what I find.
Regards, Stephen