I wanted to mark this solved send a brief note of thanks. After a month (off and on) of troubleshooting, your insightful questions helped to narrow in on the problem and helped me to ultimately determine that it was a line discipline (somehow) attached to the this ttyACM device each time it was created. This was ultimately not a USB or ACM device problem. The code now calls tcsetattr() to set the port to raw mode (instead of improperly assuming that it already was which had worked previously). I've read this mailing list for the last week or so and it's amazing how much work you guys do. Please accept my thanks for your help with this problem and well as for all the work you all do for the community. Mike > After adding this code, the sample application appears to run > - yeah! I'll do some more complete testing today to verify. > > A couple of follow up questions if you don't mind: > - For the cdc_acm driver, is the bit rate in termios just ignored? > - Similarly, are VMIN and VTIME used? > - Any idea why previous releases worked fine but a line > discipline is now applied to this cdc_acm port in the current release? > > Thanks > > Mike-- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
