From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755110AbaHUNL5 (ORCPT ); Thu, 21 Aug 2014 09:11:57 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:14283 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754530AbaHUNL4 (ORCPT ); Thu, 21 Aug 2014 09:11:56 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 21 Aug 2014 06:02:13 -0700 Message-ID: <53F5F019.10308@nvidia.com> Date: Thu, 21 Aug 2014 16:11:53 +0300 From: Mikko Perttunen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Stephen Warren , CC: , , , Subject: Re: [PATCH v2 5/5] ARM: tegra: Add thermal reset (thermtrip) support to PMC References: <1407933685-12404-1-git-send-email-mperttunen@nvidia.com> <1407933685-12404-6-git-send-email-mperttunen@nvidia.com> <53F5042A.7020603@wwwdotorg.org> In-Reply-To: <53F5042A.7020603@wwwdotorg.org> X-NVConfidentiality: public Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/08/14 23:25, Stephen Warren wrote: > On 08/13/2014 06:41 AM, Mikko Perttunen wrote: >> This adds a device tree controlled option to enable PMC-based >> thermal reset in overheating situations. Thermtrip is supported on >> Tegra30, Tegra114 and Tegra124. The thermal reset only works when >> the thermal sensors are calibrated, so a soctherm driver is also >> required. > > If calibration is required, presumably the soctherm must initialize > before this thermtrip code can initialize, or this thermtrip logic might > be triggered by uncalibrated sensors? SOCTHERM requires that each sensor be explicitly enabled before it gives readings. If a sensor is not enabled, the temperature given by the register (and used to trigger thermtrip) will be zero. So in order for a thermtrip shutdown to be caused before soctherm is initialized, the thermtrip temperature would have to be programmed to below zero (the default value is 105C), in which case an immediate shutdown would probably be in order anyway (unless the user uses LN2 or something to cool the soc below zero). > > If so, then there needs to be some explicit mechanism to force the two > drivers into probing in the right order. Because of the above, I think it isn't necessary to probe these in order. Cheers, Mikko