Re: Dell Optiplex GX240, ACPI and APIC

[Tear <tarrqt@yahoo.com>]

--- Andrew Morton <akpm@linux-foundation.org> wrote:

> On Sat, 12 May 2007 07:04:25 -0700 (PDT) Tear <tarrqt@yahoo.com> wrote:
> 
> > Summary: If ACPI is not enabled but APIC is,
> > then there is trouble on Dell Optiplex GX240.
> > If both are enabled or if both are disabled, then
> > everything is fine. The attached patch removes
> > Dell Optiplex GX240 from the ACPI blacklist.
> > 
> > ---
> > 
> > Hello,
> > 
> > I have a Dell Optiplex GX240 and when I boot Linux, ACPI
> > gets set up by only acpi=ht. dmesg shows the following line:
> > 
> >    DELL GX240 detected: force use of acpi=ht
> > 
> > Everything seemed to be fine. However, I discovered that
> > everything is not fine. The USB controller works so slowly
> > that copying a few (uncached) 1 megabyte large photos from
> > a USB-enabled digital camera takes many minutes instead of
> > a couple of seconds.
> > 
> > I am using Linux 2.6.21.1 on a Debian 4.0 ("Etch") system.
> > 
> > I thought that this might be related to ACPI. So I tried
> > to boot with _only_ "acpi=force" appended to the kernel
> > command line. Voila, the USB controller started to work
> > at full speed and copying photos from my digital camera
> > took only seconds.
> > 
> > I tested the system with "acpi=force" and could not find
> > anything which did not work. So, can we please remove
> > Dell Optiplex GX240 from the blacklist in
> > 
> > ..../arch/i386/kernel/acpi/boot.c
> > 
> > ? The attached patch does just that: It removes Dell
> > Optiplex GX240 from the ACPI blacklist.
> > 
> > I thought that this might be related to interrupts and
> > APIC as well. (Note that this is APIC, not ACPI.) I tried
> > booting with _only_ "noapic" and "nolapic" appended to the
> > command line. Again, the USB controller started to work
> > at full speed.
> > 
> > If removing Dell Optiplex GX240 from the ACPI blacklist
> > is not wanted/possible, then is there a way to disable
> > APIC and LAPIC (note that this is APIC not ACPI) by
> > default on Dell GX240 machines? (I.e. Can one patch
> > the kernel so that APIC and LAPIC isn't used on
> > these machines? - I know that I can use the noapic
> > and nolapic options on the kernel command line.)
> > 
> > Thank you for your attention.
> > 
> > - Tear
> > 
> > Note: Please include me in CC of your replies.
> > 
> > 
> > --- linux-2.6.21.1.orig/arch/i386/kernel/acpi/boot.c	2007-05-01 17:10:30.000000000 +0300
> > +++ linux-2.6.21.1/arch/i386/kernel/acpi/boot.c	2007-05-01 20:31:53.000000000 +0300
> > @@ -971,14 +971,6 @@
> >  	 },
> >  	{
> >  	 .callback = force_acpi_ht,
> > -	 .ident = "DELL GX240",
> > -	 .matches = {
> > -		     DMI_MATCH(DMI_BOARD_VENDOR, "Dell Computer Corporation"),
> > -		     DMI_MATCH(DMI_BOARD_NAME, "OptiPlex GX240"),
> > -		     },
> > -	 },
> > -	{
> > -	 .callback = force_acpi_ht,
> >  	 .ident = "HP VISUALIZE NT Workstation",
> >  	 .matches = {
> >  		     DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
> > 
> 
> Thanks.  Let's cc the acpi list.
> 
> The origin of that blacklist entry appears to be lost in the mists of time.
> git-blame got tripped up by an intervening Lindent run and my gittiness
> is insufficient for tracking changes before that.
> 

Mr. Morton,

I have already sent a very similar e-mail to the linux-acpi
mailing list. Please see the following for that:

http://marc.info/?l=linux-acpi&m=117856470816834&w=2

I haven't received a reply and that is why sent this e-mail
to the linux-kernel mailing list.

I would be very pleased to see the removal of Dell Optiplex
GX240 from the ACPI blacklist.

Is there a blacklist for APIC? (Note that this is APIC,
not ACPI.)

Thank you.

Tear



       
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