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02606
Contributor
Contributor
2,866 Views
Registered: ‎05-27-2009

Changing UART BAUD rate effects boot success

Using Uart 16550 I find that when the device tree is set to 9600 the ML405 boots to

root:~> ### Application running ...

 

(well that's good news just what I want) However

 

If I change the baud rate to 115200, the code stalls at

Finalizing device tree ...

 

I'm really amazed how easily the train can run off the track!

 

Comments as to this odd behavior would be appreciated.

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mamisadegh2
Observer
Observer
2,842 Views
Registered: ‎06-15-2010

Dear Sir

I tried to generate the same condition as yours in my system to test if the same thing happens in my case.

 

At 9600 every thing is Ok. system comes up properly.

At 115200 as you said, we have problems, and there is no output.

 

however, as i tested, at other baud rates, smaller than 115200, such as 57600 system works properly.

So the problem should not be related to device tree or some thing like this, it should be mainly related to UART 16550 and its related drivers.

 

by the way, i performed a small search in EDK forums and i noticed this:

http://forums.xilinx.com/t5/EDK-and-Platform-Studio/Problem-about-XPS16550-UART-with-baud-rate-115200/td-p/67180

 

may be, it is the same problem as what you are considering here.

what is the solution to this problem? i dont know !

 

may be one solution is to switch to uart lite.

 

Regards

Mohammad Sadegh Sadri.

 

 

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