On Sat, Jul 08, 2017 at 10:38:03AM +0200, Greg Kroah-Hartman wrote: > Overall, the idea looks sane to me. Keeping userspace from opening a > tty that the kernel has opened internally makes sense, hopefully > userspace doesn't get too confused when that happens. I don't think we > normally return -EBUSY from an open call, have you seen what happens > with apps when you do this (like minicom?) > I tested this wil minincom, picocom and commands like "echo foo > /dev/ttyS0". They all correctly report "Device or resource busy". I have addressed all the comments you made. I have also split the patch into three. Following is summary of each. Patch 1: introduces the tty_kopen function and checks for TTY_KOPENED Patch 2: updates speakup code to use tty_kopen instead of tty_open_by_driver Patch 3: reverses the export of tty_open_by_driver Thanks, Okash _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel