Created attachment 26433 [details]
dmesg output

Created attachment 26434 [details]
acpidump output

Created attachment 26435 [details]
'grep . /proc/acpi/battery/*/*' output

(In reply to comment #0)
> Everything worked fine on CentOS5 (2.6.18) but broke after upgrade to Fedora.
> Now remaining capacity is shown as 'unknown' right after boot, but charging
> state is 'charged'. 

So the problem only exists when AC is plugged and the battery is full charged, right?
Please unplug the AC for a while and attach the output of "grep . /proc/acpi/battery/*/*"

Created attachment 26632 [details]
'grep . /proc/acpi/battery/*/*' output after AC unplug

(In reply to comment #4)
> So the problem only exists when AC is plugged and the battery is full
> charged,
> right?
Yes. And only right after boot.
If I unplug AC for several seconds (until KDE powerdevil shows green dashes) and then plug it back, then battery capacity is detected correctly until next reboot in all states (charged,charging,discharging).
Attached is a battery state two seconds after AC unplug.

This seems to be an AML code problem to me.

This is the package that contains the battery status.
            Name (PBST, Package (0x04)
            {
                0x00,
                0xFFFFFFFF,
                0xFFFFFFFF, /* battery remaining capacity */
                0x2710
            })

And this is the AML code that returns the battery remaining capacity,
                If (LEqual (Local1, 0x01))
                {
                    If (And (0x04, \_SB.PCI0.LPCB.EC0.BATF))
                    {
                        Store (\_SB.PCI0.LPCB.EC0.B1FC, Index (PBST, 0x02))
                    }
                    Else
                    {
                    }
                }
                Else
                {
                    Store (\_SB.PCI0.LPCB.EC0.MBRM, Index (PBST, 0x02))
                }
we can see that the battery remaining capacity field is not set in some cases(maybe the ACPI plugged && battery full charged case?)
And battery remaining capacity 0xFFFFFFFF may be reported to OS in this case.

To verify this, I'll attach a custom DSDT and it would be great if you can apply it and see if the problem goes away.

Created attachment 26645 [details]
custom UPBS method

please boot a kernel that newer than 2.6.33.
mount debug fs.
run "cat custom_UPBS.hen > /sys/kernel/debug/acpi/custom_method".
and then see if the battery status is reported correctly.

custom UPBS ASL code:
DefinitionBlock ("", "UPBS", 1, "", "", 0x20080715)
{
  External (\_SB_.BAT1.PBST, PkgObj)
  External (\_SB_.POSW, MethodObj)
  External (\_SB.PCI0.LPCB.EC0.MCUR)
  External (\_SB.PCI0.LPCB.EC0.BFFG)
  External (\_SB.PCI0.LPCB.EC0.BATF)
  External (\_SB.PCI0.LPCB.EC0.B1FC)
  External (\_SB.PCI0.LPCB.EC0.MBRM)
  External (\_SB.PCI0.LPCB.EC0.BA1C)
  External (\_SB.CM26)
  External (\_SB.PCI0.LPCB.EC0.MBVG)
  External (\_SB.PCI0.LPCB.EC0.MBTC)

  Method (\_SB_.BAT1.UPBS, 0, NotSerialized)
  {
                Store (\_SB.PCI0.LPCB.EC0.MCUR, Local5)
                Store (POSW (Local5), Index (PBST, 0x01))
                Store (\_SB.PCI0.LPCB.EC0.BFFG, Local1)
                If (LEqual (Local1, 0x01))
                {
                        Store (\_SB.PCI0.LPCB.EC0.B1FC, Index (PBST, 0x02))
                }
                Else
                {
                    Store (\_SB.PCI0.LPCB.EC0.MBRM, Index (PBST, 0x02))
                }

                Store (\_SB.PCI0.LPCB.EC0.BA1C, Local1)
                Store (Local1, \_SB.CM26)
                Store (\_SB.PCI0.LPCB.EC0.MBVG, Index (PBST, 0x03))
                If (LNotEqual (Local5, 0x00))
                {
                    If (\_SB.PCI0.LPCB.EC0.MBTC)
                    {
                        Store (0x02, Index (PBST, 0x00))
                    }
                    Else
                    {
                        Store (0x01, Index (PBST, 0x00))
                    }
                }
                Else
                {
                    Store (0x00, Index (PBST, 0x00))
                }
  }
}

Hi,

Are you sure about version?

[root@localhost debug]# uname -a
Linux localhost 2.6.34-20.fc14.i686.PAE #1 SMP Wed Jun 2 12:53:34 UTC 2010 i686 i686 i386 GNU/Linux
[root@localhost debug]# pwd
/sys/kernel/debug
[root@localhost debug]# LANG=C ls -l
total 0
drwxr-xr-x.  3 root root 0 Jun  5 09:45 ath5k
drwxr-xr-x. 35 root root 0 Jun  5 09:45 bdi
drwxr-xr-x.  3 root root 0 Jun  5 09:45 boot_params
drwxr-xr-x.  4 root root 0 Jun  5 09:45 dri
drwxr-xr-x.  2 root root 0 Jun  5 09:45 dynamic_debug
-r--r--r--.  1 root root 0 Jun  5 09:45 gpio
drwxr-xr-x.  3 root root 0 Jun  5 09:45 hid
drwxr-xr-x.  3 root root 0 Jun  5 09:45 ieee80211
drwxr-xr-x.  2 root root 0 Jun  5 09:45 kprobes
drwxr-xr-x.  2 root root 0 Jun  5 09:45 mce
drwxr-xr-x.  2 root root 0 Jun  5 09:45 mmc0
-rw-r--r--.  1 root root 0 Jun  5 09:45 sched_features
drwxr-xr-x.  2 root root 0 Jun  5 09:45 slow_work
drwxr-xr-x.  6 root root 0 Jun  5 09:45 tracing
drwxr-xr-x.  3 root root 0 Jun  5 09:45 usb
drwxr-xr-x.  2 root root 0 Jun  5 09:45 virtio-ports
drwxr-xr-x.  2 root root 0 Jun  5 09:45 x86
drwxr-xr-x.  4 root root 0 Jun  5 09:45 xen


It seems that 2.6.34 doesn't have this feature yet.

Oh, you need to set CONFIG_ACPI_DEBUG first.

It seems to me that upgrade to the latest Intel's Verified reference BIOS for Quanta TW3A (which Benq R55E apparently is) platform solved this problem.

Thanks for indirectly pointing me to a solution.