ttyUSB0/1 disappearing upon execution

Technical discussions related to any XMOS development kit or reference design. Eg XK-1A, sliceKIT, etc.
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Gravis
Experienced Member
Posts: 75
Joined: Thu Feb 02, 2012 3:32 pm

ttyUSB0/1 disappearing upon execution

Post by Gravis »

i'm back on linux now (yay!) and i want to send my XC-1A data via. however, when i execute a program (execution over jtag), both FTDI devices /dev/ttyUSB0 and /dev/ttyUSB1 disappear as they are disconnect according to dmesg.
[15632.983993] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[15632.984074] ftdi_sio 6-4:1.0: device disconnected
[15632.997945] ftdi_sio ttyUSB1: FTDI USB Serial Device converter now disconnected from ttyUSB1
[15632.997980] ftdi_sio 6-4:1.1: device disconnected
i can execute programs repeatedly so there must be another way to communicate with it.

is this normal? am i doing something wrong? is there another device to send info to?

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segher
XCore Expert
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Joined: Sun Jul 11, 2010 1:31 am

Post by segher »

Hi Gravis,

There is no proper way for the Linux device driver to detect that interface 1
is a JTAG instead of a UART, so it claims both interfaces. Now the tools
want to have the JTAG, so they disconnect the ftdi_sio driver from it. They
also disconnect it from interface 2; I don't know why, maybe they want
access to the UART themselves, maybe they simply disconnect the whole
device from ftdi_sio.

You could try my "term" program from http://git.infradead.org/users/segher/dis-xs1.git,
the tools cannot disconnect that (but they might not want to run then, I
haven't tried). It uses the UART at 115200 8N1 no handshake. If you have
problems with it, I've seen you on IRC before :-)