Messages in this thread | | | Subject | RE: [PATCH] [RESEND] Add Dell laptop backlight brightness display | From | Michael E Brown <> | Date | Mon, 06 Feb 2006 21:43:16 -0600 |
| |
Matthew, Andrew, (sorry, I'm not subscribed to l-k, so I'm just starting a new thread.)
I would _strongly_ suggest that this patch _not_ go in. This driver uses hardcoded values that are subject to change without notice. It is perfectly legitimate for future versions of Dell BIOS to interpret pokes to cmos location 0x99 as the command to format your hard drive.
The proper way to do this is using libsmbios. The project page is at http://linux.dell.com/libsmbios/main. Using libsmbios, plus the already-included dcdbas kernel driver, you can correctly do brightness control. If you would like to write a proper brightness control, it can be done entirely in user space, and I could help you.
There are specific smbios structures, proprietary to Dell, that are documented in libsmbios. These structures, properly decoded, tell the proper port to use to control this. This is guaranteed to work across BIOS versions and not to format your hard drive. :-)
Libsmbios is 100% open source (dual GPL/OSL license).
-- Michael Brown Libsmbios maintainer
- 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/
| |