Re: LMSENSORS: 2.6.26-rc, enabling ACPI Termal Zone support costs sensors

From: Rene Herman
Date: Mon Jun 23 2008 - 08:34:36 EST


On 23-06-08 13:57, Jean Delvare wrote:

On Mon, 23 Jun 2008 12:24:06 +0200, Rene Herman wrote:

No Jean, this is totally unacceptable. No matter how you want to call things, 2.6.26 is going to break important functionality on millions of systems and you simply do not get to do that.

No, it's not going to be the end of the world that you predict. Please
stop being alarmist, it really doesn't help.

We are going to break hardware monitoring for users who upgrade to
kernel 2.6.26 by themselves and have enabled option "THERMAL"

Which is an option selected by ACPI_THERMAL, for which I quoted the help text earlier. Basically everyone with ACPI enabled will have it enabled. Rather wide-spread, that is.

and are using lm-sensors <= 2.10.6. I suspect this is a relatively
small number of users

Yes, right. All not completely new systems, all completely new slackware and derived systems... "relatively" is a word very much needed here.

I really cannot believe you guys are actually arguing this. It seems that me being tired and short pulled this in to senseless country but can we please concentrate on the issue?

libsensors dictated the ABI rule that the hwmon directories must have device backlinks; the new ACPI Thermal Zone hwmon interface breaks that bit of ABI. It is not relevant that that ABI may have gotten to be as a result of unfortunate programming on the userspace side -- the only thing relevant is that it IS. lm-sensors 2 is on millions of systems out there. This is not meant agressively, or whatever you guys seem to want to read in my words, it's un undeniable fact.

and these are also the ones who are presumably skilled enough to go
to http://www.lm-sensors.org/, find the patch they need, and apply it
to libsensors themselves.

At times there can obviously be situations where it's fine to require new userspace but in this case we have a new userspace which hasn't even been released yet, we have a ton of _different_ userspace depending on that bit of core userspace, we have breakage of the important kind (as you no doubt know, sensors can be pretty vital, although admittedly it's not silent breakage at least) and we have an opportunity to just say "okay, we'll apply a 1 line patch and be done with it" which avoids any and all problems. Why are you arguing this?

Can you comment on the last patch posted? It's trivial:

http://lkml.org/lkml/2008/6/22/243

It's trivial and wrong, so thanks but no thanks. The bug is in
libsensors, we fix it in libsensors.

This cannot be the reason, because it's not wrong. We just need a device backlink. Basically, any single one will do. It's just about keeping lm-sensors 2 happy.

Rene.
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