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List:       mandrake-cooker
Subject:    Re: [Cooker] Laptop Problems
From:       Juan Quintela <quintela () mandrakesoft ! com>
Date:       2002-02-24 15:58:12
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>>>>> "randy" == Randy Welch <rswelch@sonic.net> writes:

Hi

randy> What is it with Dells and others laptops?

randy> ThinkPads ( or at least the A2X  series ) seem to resist any attempts
randy> by the kernel to enable it:

problem is that there are different grades of APIC brokeness:

randy> syslog:Feb 19 21:13:10 randyspc kernel: Local APIC disabled y BIOS --
randy> reenabling.
randy> syslog:Feb 19 21:13:10 randyspc kernel: Could not enable APIC!

grades of APIC support:

- if you don't have APIC you are out of luck
  * some SMP machines, new beards with promise as second ide
    controller on board,  GX chipsets are also in that cathegory.
- we work with/withuout APIC 
  this is supposed to be the majority of the hardware
- we have a broken APIC, we now it, and we will not let you to
  activate it, doesn't matter how many times you asked for it.
  this IBM laptop is a good example
- we have a broken APIC implementation, but we announce that we have
  an APIC, and if you try to use it, we will hang.
  dell laptops are in this group.

If you can came with a clean solution for this problem, I am all ears.
Notice that:
- APIC is better (PIC is a technology that is 30 years old, and it was
  not good indeed at that time).
- when you try to activate APIC, if you don't have APIC, no problem,
  it will just ignore it, if you have one, you are supposed to have
  one that works, otherwise don't let the APIC to be activated.

Until 2.4.18-21mdk, if you put a noapic option to the kernel, he will
found that you _really_ had an apic, and will think, Oh, user is
confused, I will use the APIC anyways.  From 21mdk, if user told in
the command line noapic, kernel will not try to use APIC at all.

randy> This issue reminds me of the 8.0 trackpoint mouse issue on the
randy> thinkpads. ( it was inoperative...  )

that was a really strange thing, and the patch, it is still not
completely clear why it is needed.

randy> Why not build a 'laptop' kernel with APIC turned off? Especially with
randy> the changes done to make those folks with r128 based laptops.

Because:
1- there is not only laptops, some SMP system can have the same
   problem (yes, there are buggy BIOS all around the world).
2- it is supposed that the r128 problem is fixed.
3- having _yet_ another 4 kernels will be only more problems. Notice
   that there is not only having _other_ kernel, it is just having
   also _another_ installation CD.
4- Trying hard to get a way to detect that laptops at boot and try not
   to use the CD, just that it is difficult (APIC is one of the first
   things to be initialized, and for knowing what machine we are, we
   need to have initialized a couple of things).

Later, Juan.

-- 
In theory, practice and theory are the same, but in practice they 
are different -- Larry McVoy

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