Most recent kernel where this bug did not occur: 2.6.22.x Distribution: Slackware 12 Hardware Environment: Athlon64 3000 + nForce3 150 on Aspire 1511 LMi Software Environment: none Problem Description: With recent kernels (2.6.23-rc3, maybe 2.6.23-rc2 but I'm not sure), the battery information is not available anymore on some laptops. Dmesg info for different kernel versions appended. Steps to reproduce: Maybe specific to my hardware. It used to have a DSDT replacement for old kernels (2.6.16 for instance), but since 2.6.19 up to 2.6.22 it was not necessary. Now, it does work with neither original nor fixed DSDT.
Created attachment 12366 [details] dmesg for 2.6.22.1-cfs19, which works nice Please note that even dmesg says battery absent, it ** is ** detected and usable through /proc/acpi/battery/BAT1/state and info.
Created attachment 12367 [details] dmesg for 2.6.23-rc3, which doesn't detect the battery The battery is not detected anymore in /proc/acpi/battery/BAT1/state, info and so.
Created attachment 12369 [details] Undelete register query function Please check if this patch helps.
patch in comment #3 checked into acpi tree.
I will test the patch today. Moreover, I can confirm this is a 2.6.23-rc3 regression (2.6.23-rc2 still works).
2.6.23-rc3+patch = OK It now works. Thanks a lot
patch in comment #3 shipped in 2.6.23-rc3-git1 closed