Bug 4546 - A fix for APM on Acer Extensa 501T and possibly others.
A fix for APM on Acer Extensa 501T and possibly others.
Status: CLOSED CURRENTRELEASE
Product: Red Hat Linux
Classification: Retired
Component: kernel (Show other bugs)
6.0
i386 Linux
medium Severity medium
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Assigned To: Michael K. Johnson
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Depends On:
Blocks:
  Show dependency treegraph
 
Reported: 1999-08-16 12:09 EDT by Michael McConachie
Modified: 2013-09-02 01:52 EDT (History)
1 user (show)

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Fixed In Version:
Doc Type: Bug Fix
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Clone Of:
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Last Closed: 2000-02-03 22:10:46 EST
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RHEL 7.3 requirements from Atomic Host:
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Description Michael McConachie 1999-08-16 12:09:24 EDT
This ended up comming in over a support ticket.  The
informations eems to be quite valid.  Submitted as a bug in
case it's any use to others...

Bios of "ACER EXTENSA 501T"
return     apm_bios_info.cseg=0xfbbd and
apm_bios_info.offset=0x500000
(this is bad adress)
working is apm_bios_info.cseg=0xfbbd and
apm_bios_info.offset=0

--- apm.c.orig  Fri Jan 15 07:57:25 1999
+++ apm.c       Mon Jun 28 14:36:29 1999
@@ -1349,7 +1349,7 @@
                 __va((unsigned long)0x40 << 4));
        _set_limit((char *)&gdt[APM_40 >> 3], 4095 - (0x40
<< 4));

-       apm_bios_entry.offset = apm_bios_info.offset;
+       apm_bios_entry.offset = apm_bios_info.offset &
0xffff;
        apm_bios_entry.segment = APM_CS;
        set_base(gdt[APM_CS >> 3],
                 __va((unsigned long)apm_bios_info.cseg <<
4));

--

References: http://www.al.unipmn.it/~sitta/linux503.html
            http://www.al.unipmn.it/~sitta/linux/apm.html

   --michael
Comment 1 Michael K. Johnson 1999-09-25 00:44:59 EDT
Doug, could you please evaluate this?
Comment 2 Bernhard Rosenkraenzer 1999-11-12 13:21:59 EST
Kernel problem, not apmd.
Doesn't apply to current kernel - guess we can close this?
Comment 3 Bernhard Rosenkraenzer 2000-01-31 15:10:59 EST
This is a kernel problem - it's fixed in 2.3.x (CONFIG_APM_BAD_ENTRY_OFFSET),
but it's still present in kernel 2.2.14.
The patch mentioned above doesn't apply to current 2.2 kernels;
the line in question is line 1353 in arch/i386/kernel/apm.c 2.2.14-1.2.0.
I don't see a problem with this patch - IMO it can get in.
Comment 4 Alan Cox 2000-08-22 10:31:30 EDT
Its already handled differently in current 2.2

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