linux-kernel - Re: HPET : Legacy Routing Replacement Enable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20061027024238.GC58088@muc.de>
Date:	Fri, 27 Oct 2006 04:42:38 +0200
From:	Andi Kleen <ak@....de>
To:	Om Narasimhan <om.turyx@...il.com>
Cc:	"Pallipadi, Venkatesh" <venkatesh.pallipadi@...el.com>,
	linux-kernel@...r.kernel.org, randy.dunlap@...cle.com,
	clemens@...isch.de, vojtech@...e.cz, bob.picco@...com
Subject: Re: HPET : Legacy Routing Replacement Enable - 3rd try.

On Wed, Oct 25, 2006 at 02:20:22PM -0700, Om Narasimhan wrote:
> I tested against five different bioses (some with 8132, some with
> CK-804 ..etc) and I observed three different patterns.
> 
> 1. HW is LRR capable, HPET ACPI it is 1, timer interrupt is on INT2.
> Before the fix: Linux cannot get timer interrupts on INT0, goes for ACPI 
> timer.

What ACPI timer?  I don't think we have any fallback for int 0.

Not sure what you mean with INT2. Pin2 on ioapic 0 perhaps?

> After the fix : Works fine. This is according to hpet spec.

On what exact motherboard was that?

> 
> To handle case 3, I removed all references to acpi_hpet_lrr, explained
> this case in the code and decided to solely rely on the command line
> parameter for LRR capability. Rational for this approach is ,

This means the systems which you said fixes this would need the command
line parameter to work? 

> 1. At present, there are not many BIOSes which implement LRR (correctly)
> 2. People would see the bootup message (MP-BIOS bug...) if LRR is
> enabled and no timer interrupt on INT0. They can pass the hpet_lrr=1
> to make everything work fine.
> Is it the right approach?

Generally we try to work everywhere without command line parameter
unless something is terminally broken. 
-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/