Re: apm-bios and rtc

C. Scott Ananian (
Mon, 2 Mar 1998 22:56:58 -0500 (EST)

On Mon, 2 Mar 1998, Garst R. Reese wrote:

> C. Scott Ananian wrote:
> > Could you confirm that 0x01FF *doesn't* work, even if rtc support is
> > turned off?
> YES, confirmed. But, I also discovered an interaction with the blank
> time set with setterm -blank and the blank time set in my bios.
> works if I have X on another VC. Now I am not certain if it was
> disabling rtc or setting the bios blank time to 1 that made things
> appear to work :( Testing screen blanking is sorta boring :)

OK. But if setting the constant to 0x0100 was an enabling factor, I
should probably document it or make it a config option.

> > > I also noticed in console.c that apm screen blanking is called if
> > > CONFIG_APM is set. Shouldn't this be ifdef CONFIG_APM_DISPLAY_BLANK ?
> >
> > No, see drivers/char/apm_bios.c, function apm_display_blank.
> I did look at that code. I just did not see the point of even calling
> apm_display_blank if CONFIG_APM_DISPLAY_BLANK is not set, which is
> should not be if CONFIG_APM is not set.

I'm not the original author, of course, but reading the comments at the
top of apm_bios.c makes clear that the intent was that only CONFIG_APM
be visible outside of the apm_bios module, even if this meant an
unnecessary (but harmless) call to apm_display_blank. I think that's
valid reasoning.
@ @
C. Scott Ananian: / Declare the Truth boldly and
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