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i.MX6 dte-mode doesn't transmit chars on UART

Question asked by Marco Cavallini on May 4, 2016
Latest reply on May 16, 2016 by Marco Cavallini

Hello,

I already started a similar thread and I've read a plenty of documents saying that dte-mode switches RTS/CTS signals on the CPU pins (MUX).

Okay, let's suppose that it is true despite the evidence demonstrate the opposite, and I can explain why.

I tested this with linux kernel 3.14.28 and 4.1.15 and 4.5.2 without success.

 

My questions are:

  1. Why if I set fsl,uart-has-rtscts; + fsl,dte-mode; the UART manages the RTS signal during my serial transmission but there are no chars going out from the TX pin?
  2. Is there any silicon bug in this CPU or any special CPU setting, to have RTS/CTS signals working when I transmit chars?

 

Is there any NXP/Freescale engineer, FAE, specialist out there able to explain this behaviour?

 

P.S. If you need more details on this, please read this thread and the links inside it: https://community.freescale.com/thread/390320

 

I already tested it monitoring the RTS and CTS signals with a scope and connecting RTS with CTS on the port I am using (&uart3 = /dev/ttymxc2).

 

Thank you in advance.

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