I.MX6ULL uart 0xff infinite receive interrupt by noise

[Sungkyun]

Hi,

I am using imx6ull kernel 4.1.15. It is connected to an old PC by UART, and noise causes an infinite 0xff Rx problem. At this time, even if the cable is removed, this phenomenon continues. Is it a chip problem? I also saw a post that says that enabling the auto baud rate detection function will solve it, but we have to fix the baud rate. Can you provide a perfect solution?

Thanks.

Sungkyun Ko

[Yuri]

@Sungkyun 
Hello,

   the following may help:

https://community.nxp.com/t5/i-MX-Processors/IMX6-UART-Receive-Continuous-0xFF/m-p/1080272

https://community.nxp.com/t5/i-MX-Processors/i-MX6-infinite-loop-in-uart-driver-rx-interrupt/m-p/626...

Regards,
Yuri.

[Sungkyun]

Hi~

It was confirmed that it returned to normal after SW Reset. But is it possible to detect whether a 0xff storm has occurred with S/W? For reference, in my case, frame error is not set when 0xff storm occurs.

Thanks.

Sungkyun Ko

[Yuri · Accepted solution]

@Sungkyun 
Hello,

   I am afraid it is not possible to detect the issue on registers level. 
Higher level protocol is required here.

Regards,
Yuri.

[igorpadykov]

Hi Sungkyun

one can try with new kernels as they have uart driver improvements, also one can

check hardware: use short shielded cable, pay attention to grounding board and PC,

try to ground them in one point.

https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applicat...

Best regards
igor