Add a new configuration flag, KBD_NORESET (0x20) to tell scprobe() not
to reset the keyboard.
IBM ThinkPad 535 has the `Fn' key with which the user can perform
certain functions in conjunction with other keys. For example, `Fn' +
PageUP/PageDOWN adjust speaker volume, `Fn' + Home/End change
brightness of LCD screen. It can also be used to suspend the system.
It appears that these functions are implemented at the keyboard level
or the keyboard controller level and totally independent from BIOS or
OS. But, if the keyboard is reset (as is done in scprobe()), they
become unavailable. (There are other laptops which have similar
functions associated with the `Fn' key. But, they aren't affected by
keyboard reset.)
ThinkPad 535 doesn't have switches or buttons to adjust brightness and
volume, or to put the system into the suspend mode. Therefore, it is
essential to preserve these `Fn' key functions in FreeBSD. The new
flag make scprobe() skip keyboard reset.
If this flag is not set, scprobe() behaves in the same say as before.
(If we only knew a way to detect ThinkPad 535, we could skip keyboard
reset automatically, but...)
a2fc20d086