linux-kernel - Re: [PATCH v2] hwmon: Update Documentation/hwmon/sysfs-interface

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: <20070917184310.GN30825@tree.beaverton.ibm.com>
Date:	Mon, 17 Sep 2007 11:43:11 -0700
From:	"Darrick J. Wong" <djwong@...ibm.com>
To:	Jean Delvare <khali@...ux-fr.org>
Cc:	"Mark M. Hoffman" <mhoffman@...htlink.com>,
	Henrique de Moraes Holschuh <hmh@....eng.br>,
	linux-kernel@...r.kernel.org, lm-sensors@...sensors.org,
	haveblue@...ibm.com
Subject: Re: [PATCH v2] hwmon: Update Documentation/hwmon/sysfs-interface

On Mon, Sep 17, 2007 at 07:28:08PM +0200, Jean Delvare wrote:
> Thanks for the update. I have some more comments. And sorry if it looks
> like nitpicking, but this is a standard interface we're defining so we
> better make sure that we get it right.

Agreed. :)
> 
> First of all, please think of a better subject line for this patch.
> "Update Documentation/hwmon/sysfs-interface" is too vague when your
> patch is rather specific.

Will change to:
"Add power meter spec to Documentation/hwmon/sysfs-interface"

> > +power[1-*]_average_lowest	Historical average minimum power use
> > +				Unit: microWatt
> > +				RO
> 
> How useful are historical extremes of an average?

I don't know if anybody ever really requires this data, but the device
I'm talking to records the extremes in hardware, so I put it in the driver.

> > +power[1-*]_high_low_reset	Reset input_highest/input_lowest.
> > +				WO
> 
> I don't much like this name. It sounds like a name crafted for the
> specific feature of a given chip, while we try to use generic names for

Guilty as charged.  Since ibmpex is the only on-board power meter hardware
to which I have access, the interface proposal includes the various odd
pieces that the hardware provides in addition to the meters.  I
could take the historical extreme and reset bits out of the proposal and
put them in something like Documentation/hwmon/ibmpex.txt as extra
chip-specific features if people prefer that.

> the standard interface. I would rather go for power[1-*]_reset_history

Me too.

> if we have a single file for resetting all the extremes of a given
> channel, or power[1-*]_input_lowest_reset and
> power[1-*]_input_highest_reset if we go for a per-value reset.

The ibmpex hardware only knows how to reset all of them.

> Alternatively, we could simply make the power[1-*]_input_lowest and
> power[1-*]_input_highest files writable, and "cat power1_input >
> power1_input_lowest" (or any write?) would reset the history.

I'd prefer to leave it explicitly called out as a separate sysfs knob,
unless there are established precedents for resetting a sensor by
writing something to its sysfs file.

--D

Download attachment "signature.asc" of type "application/pgp-signature" (190 bytes)