Edgeport/8 Linux strange behavior

I have an Edgeport/8 that I’m experiencing a strange issue with.

Edgeport info:
PN: 1p 50001231 01
SN: s v13620618
PN: 301 1002 58

Linux kernel: 2.6.22-gentoo-r6
io_edgeport.c: Edgeport USB Serial Driver v2.7

I’m using it with a serial elographics touchscreen, model 1515L. Everything works fine, until the monitor is turned off and then back on again. At that point, the touchscreen still sends the events, but they seem to be queued up in the /dev/ttyUSB0 device. The strange thing is that after maybe 5-10 seconds of touchscreen events, they seem to be sent to the Xorg drivers and are shown, but only upon new input. It seems like there is a buffer that fills up and only sends the old events to the PC to accommodate the new events coming from the touchscreen.

If I “cat /dev/ttyUSB0” the events are there.

I have tested this scenario with a cheapie PL2302 usb-serial dongle and it works fine.

Any help would be greatly appreciated.


Unfortunately we do not have any mechanisms currently to troubleshoot specific serial device related problems when it comes to Linux (like we do with Windows). Since you’re using an older chipset EP8, I’d like to get you a newer chipset EP/8 that has a completely different buffering scheme. You may not see this problem anymore.

But, I’ll also have to have you “patch” your current kernel to support this newer TI device. You need to have some Linux experience in patching kernels.

Do you want to try this route? If so, please contact me directly at mikes@digi.com

Mike Swift

Thanks Mike! It works great now!!!