From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Schaeckeler Subject: Re: [PATCH 0/1] i2c: imc: Add support for Intel iMC SMBus host controller. Date: Sun, 5 Apr 2020 14:40:59 -0700 (PDT) Message-ID: <20200405214059.91F97899799@corona.crabdance.com> References: <1582498270-50674-1-git-send-email-schaecsn@gmx.net> <20200405180510.GD6313@kunai> Reply-To: schaecsn@gmx.net Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Return-path: Received: from mout.gmx.net ([212.227.15.19]:44335 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726887AbgDEVlI (ORCPT ); Sun, 5 Apr 2020 17:41:08 -0400 In-reply-to: <20200405180510.GD6313@kunai> (message from Wolfram Sang on Sun, 5 Apr 2020 20:05:10 +0200) Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: wsa@the-dreams.de Cc: luto@kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, andy.shevchenko@gmail.com Hello Wolfram, > > > This patch is based on Andy Lutomirski's iMC SMBus driver patch-set > > > https://lkml.org/lkml/2016/4/28/926. It never made it into the kerne= l. I hope > > > this rewrite will: > > > > > > > > > Overview > > > > > > Modern Intel memory controllers host an SMBus controller and connect= ion to > > > DIMMs and their thermal sensors. The memory controller firmware has = three modes > > > of operation: Closed Loop Thermal Throttling (CLTT), Open Loop Therm= al > > > Throttling (OLTT) and none. > > > > > > - CLTT: The memory controller firmware is periodically accessing the= DIMM > > > temperature sensor over the SMBus. > > > > > > > > > I think this is great! One question, though: what happens if the > > system is in CLTT mode but you disable CLTT and claim the bus for too > > long? For example, if there's an infinite loop or other lockup which > > you have the tsod polling interval set to 0? Does the system catch > > fire or does the system do something intelligent like temporarily > > switching to open loop? > > Any news on this question? Thank you for your interest in this patch. You can read my reply here https://lkml.org/lkml/2020/3/1/216 Stefan