mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Mikael Pettersson <mikpe@csd.uu.se>
To: Zwane Mwaikambo <zwane@holomorphy.com>
Cc: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH][2.5-AC] Forced enable/disable local APIC
Date: Thu, 7 Nov 2002 17:14:29 +0100	[thread overview]
Message-ID: <15818.37221.445746.346901@kim.it.uu.se> (raw)
In-Reply-To: <Pine.LNX.4.44.0211052138060.27141-100000@montezuma.mastecende.com>

Zwane Mwaikambo writes:
 > +int enable_local_apic_flag __initdata = 0; /* 0=probe, 1=force, 2=disable e.g. DMI */
...
 > +	if (enable_local_apic_flag == 1)
 > +		goto force_apic;
 >  
 >  	switch (boot_cpu_data.x86_vendor) {
 >  	case X86_VENDOR_AMD:
 > @@ -642,6 +661,7 @@
 >  		goto no_apic;
 >  	}
 >  
 > +force_apic:
 >  	if (!cpu_has_apic) {
 >  		/*
 >  		 * Some BIOSes disable the local APIC in the

Of what use is the force case? If someone boots with "lapic" on a CPU
where the APIC feature bit is off, then the code will rdmsr/wrmsr on
APICBASE, even though we (the kernel) haven't verified that the CPU
actually has that MSR. This is doubleplusungood.

I have no problem with the disable option.

/Mikael

  parent reply	other threads:[~2002-11-07 16:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-11-06  2:39 Zwane Mwaikambo
2002-11-06 12:26 ` Maciej W. Rozycki
2002-11-07 16:14 ` Mikael Pettersson [this message]
2002-11-07 16:25   ` Maciej W. Rozycki
2002-11-07 16:41   ` Zwane Mwaikambo
2002-11-07 16:50     ` Mikael Pettersson
2002-11-07 21:40       ` Zwane Mwaikambo
2002-11-08 12:21         ` Maciej W. Rozycki
2002-11-08 13:05           ` Zwane Mwaikambo
2002-11-08 13:22             ` Mikael Pettersson
2003-05-31  3:28               ` Brian J. Murrell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=15818.37221.445746.346901@kim.it.uu.se \
    --to=mikpe@csd.uu.se \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=macro@ds2.pg.gda.pl \
    --cc=zwane@holomorphy.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®