On Thu, Feb 01, 2007 at 06:09:24PM +0800, Aubrey Li wrote: > On 2/1/07, Russell King <[EMAIL PROTECTED]> wrote: > >On Thu, Feb 01, 2007 at 10:33:40AM +0800, Aubrey Li wrote: > >> On 2/1/07, Alan <[EMAIL PROTECTED]> wrote: > >> >What code is running on that console at the time. Most likely that user > >> >code is also saving/restoring terminal settings so overwrite yours > >> > > >> > >> I implemented the serial driver by myself, :). See the attachment. > >> I didn't save/restore terminal setting in the my_set_termios(). > >> > >> I trace this back till tty_tioctl(..., unsigned long arg), everytime I > >> type "ENTER" key, > >> the argument "arg" passed into tty_ioctl() is the address of a termios > >> structure, which include wrong c_cflag. > > > >If userspace is issuing an ioctl to re-enable crtscts, and the kernel > >is obliging, how can this be a kernel bug? > > But the fact is not. > 1) kernel boot up and enable crtscts by default > 2) issue an ioctl to disable crtscts. > 3) not do anything but type "ENTER", kernel re-enable crtscts. > > That's wrong. Terminal setting seems not be recorded by the serial core.
serial core does not and should not "record" the terminal settings. That's the job of the tty layer. > Is it clear? No. You haven't analysed the call path causing tty_ioctl() to be invoked, so you have no basis to point the finger *anywhere* at the moment. Find out from where tty_ioctl() is called - maybe by adding a call to dump_stack(). I think you'll find it is coming from userspace. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
