On Tue, 28 Mar 2017, Ngie Cooper wrote:

On Mar 28, 2017, at 21:40, Bruce Evans <b...@optusnet.com.au> wrote:

On Wed, 29 Mar 2017, Bruce Evans wrote:

On Wed, 29 Mar 2017, Andrey Chernov wrote:
Moreover, I can't enter KDB via Ctrl-Alt-ESC in the syscons only mode
anymore - nothing happens. In the vt mode I can, but can't exit via "c"
properly, all chars typed after "c" produce beep unless I switch to
another screen and back.
All it means that syscons becomes very broken now by itself and even
damages the kernel operations.

I found a bug in screen resizing (the console context doesn't get resized).
This doesn't cause any keyboard problems.

But I suspect it is a usb keyboard problem.  Syscons now does almost
correct locking for the screen, but not for the keyboard, and the usb
keyboard is especially fragile, especially in ddb mode.  Console input
is not used in normal operation except for checking for characters on

Try using vt with syscons unconfigured.  Syscons shouldn't be used when
vt is selected, but unconfigure it to be sure.  vt has different bugs
using the usb keyboard.  I haven't tested usb keyboards recently.

I tested usb keyboards again.  They sometimes work, much the same as
a few months ago after some fixes:

The above testing is with a usb keyboard, no ps/2 keyboard, and no kbdmux.
Other combinations and dynamic switching move the bugs around, and a
serial console is needed to recover in cases where the bugs prevent any
keyboard input.

I filed a bug a few years ago about USB keyboards and usability in ddb. If you 
increase the timeout so the USB hubs have enough time to probe/attach, they 
will work.

Is that for user mode or earlier?  ukb has some other fixes for ddb now, but
of course it can't work before it finds the device.

I recently found that usb boot drives sometimes don't have enough time to
probe/attach before they are used in mountroot, and the mount -a prompt
does locking that doesn't allow them enough time if they are not ready
before it.  The usb maintainers already know about this.

I haven't taken the time to follow up on that and fix the issue, or at least 
propose a bit more functional workaround.

freebsd-current@freebsd.org mailing list
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Reply via email to