APM Console blanking not complete ?

From: Erland Hedman (erland.hedman@mvista.com)
Date: Thu Aug 01 2002 - 04:44:50 EST


With a 2.4.18 kernel running on a Dell Inspiron 8000 I have the BIOS APM
console blanking working properly for both the VT consoles as well as in X,
but only when the laptop's internal keyboard and mouse is used. After having
browsed the kernel source I guess that this blanking, turning off the power
to the laptop backlight, is handled by the APM features in the BIOS
independent of the Linux kernel.

The problem is that when I use an external mice, in this case a wireless
track ball connected to an USB port some distance from the laptop, a touch of
that mice does not turn on the laptop backlight again as I first took for
granted. It works in windows 2k ;-(

By adding a timer routine to drivers/input/mousedev.c (inspired by console.c)
I managed to "fix" my particular problem by implicitly call the
apm_console_blank() (apm.c) via the console_blank_hook used by console.c and
do the display blanking timimg independent of the BIOS settings.

This is a fix however, and does not address the problem in a general way and
I guess that USB a keyboard and possible other external devices will face the
same problem. In addition it does not sync with any BIOS settings of the
blanking time, nor does this fix reset the timer if the laptops mouse or
keyboard is touched.

So my question here (if my observations are valid) is if there are interest
to address this issue and/or if there is any work in progress for future

PS. The question is not related to DPMS, nor to the VT console's blanking
controlled by setterm. DS.

Please CC me at erland.hedman@telia.com


Best Regards, Erland Hedman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

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