Re: [PATCH] IBM T23; quirks force enable interrupts in APM set

[Alex Bligh - linux-kernel]

Thomas,

--On Saturday, 03 November, 2001 7:20 PM -0500 Thomas Hood 
<[e-mail]> wrote:

>> Summary: dmi_scan.c forces interrupt enable on during PCI BIOS
>> call for all IBM machines, which breaks T23, which needs it
>> off it seems.
> [...]
>> BIOS Vendor: IBM
>> BIOS Version: 1AET38WW (1.01b)
>> BIOS Release: 07/27/2001
>
> I would suggest that you try upgrading your firmware before
> concluding that your patch is necessary.  The latest firmware
> listed on IBM's website is version 1.03 = 1AET43WW,
> released 19 October 2001.  There have been a LOT of changes since
> version 1.01 of the firmware.  Here is IBM's changelog:

Here's the results

With my patch on 2.4.12-ac5, it was working.

First I took Arjan's pci-bridge patch alone (no BIOS
upgrade etc.). It crashes the machine on suspend.

Then I tried upgrading the BIOS firmware (to 1.03) and
the embedded controller firmware (to 1.02) - i.e. without
Arjan's patch, still running 2.4.12-ac5. It doesn't
resume properly and hung APM but didn't crash.
I believe this may be because I fixed the .config
to run the sound driver at the same time, and it oops'd,
and generally annoyed the suspend process - tsk tsk
changing too many variables at once.

Then I upgraded to 2.4.13-ac7 (which has Arjan's patch
in). All is now well. Any luck & I'll have sound working
too :-)

My conclusion is that the BIOS upgrade fixed the
necessity to call APM BIOS with interrupts off,
so the dmi_scan.c stuff which forces interrupts on
is now harmless.

So if you want to put a patch in, I guess it could
at least not break things on early T-23 BIOS's
(as that's what the dmi_scan does - as the config
option no longer has any effect), or at the /very/
least, document the fact that a BIOS & embedded
controller upgrade is extremely advisable.

[ I am recording T23 experiences at
    http://www.alex.org.uk/T23
  for anyone interested - especially in contributing]

--
Alex Bligh