Date: Mon, 13 Oct 2008 00:58:49 GMT From: Arthur Hartwig <arthur.hartwig@nokia.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/128036: Serial console mostly ignores typein to restart after shutdown Message-ID: <200810130058.m9D0wndN072568@www.freebsd.org> Resent-Message-ID: <200810130100.m9D101FJ035842@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 128036
>Category: kern
>Synopsis: Serial console mostly ignores typein to restart after shutdown
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Oct 13 01:00:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: Arthur Hartwig
>Release: 6.3
>Organization:
Nokia
>Environment:
>Description:
System with serial console.
If the system is shutdown by "shutdown -h ..." the following prompt is displayed on the console:
"The operating system has halted.
Please press any key to reboot."
Often a single keypress is not recognised; multiple keypresses are often required for the system to reboot.
>How-To-Repeat:
On system with serial console, issue
# shutdown -h now
command
>Fix:
In sys/dev/sio.c, function siocnclose() change
outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
outb(iobase + com_ier, sp->ier);
to
outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
if (rebooting == 0) {
/*
* Only restore the interrupt enables if not rebooting. If
* rebooting leave interrupts disabled, else a key press might be
* swallowed by the interrupt handler and not seen by the shutdown code.
*/
outb(iobase + com_ier, sp->ier);
}
The problem is that the shutdown code looking for a keypress on the console (loop in sys/kern/kern_shutdown.c function shutdown_halt) runs with console interrupts enabled. If the keypress generates a console interrupt then the keypress is swallowed by the console interrupt handler and not seen by the code polling for a keypress.
>Release-Note:
>Audit-Trail:
>Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200810130058.m9D0wndN072568>