From: Kurt Garloff <garloff@suse.de>

The comment in front of vt_ioctl() reads
/*
 * We handle the console-specific ioctl's here.  We allow the
 * capability to modify any console, not just the fg_console.=20
 */

Unfortunately, this does not apply to PIO_UNIMAPCLR, nor
GIO_/PIO_UNIMAP. They always operate on the current foreground
console, which is inconsistent at least. For most ioctls, the
comment is applicable.

It also causes problems, as setfont can't do the full job on
the non-fg consoles. (OK, our setfont is slightly changed to
even try it ... as you know.)

The attached patch does fix this.

I have a similar patch for 2.4, but it never got merged :-(
because not many people seem to care and I submitted in the middle
of the 2.4 series ...
It has been in UnitedLinux/SUSE kernels for ages, though.