Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752243AbaFDWam (ORCPT ); Wed, 4 Jun 2014 18:30:42 -0400 Received: from mail-ob0-f169.google.com ([209.85.214.169]:64780 "EHLO mail-ob0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751405AbaFDWak convert rfc822-to-8bit (ORCPT ); Wed, 4 Jun 2014 18:30:40 -0400 MIME-Version: 1.0 In-Reply-To: <538F18B6.7070102@ti.com> References: <1401313610-14252-1-git-send-email-nm@ti.com> <1401313610-14252-3-git-send-email-nm@ti.com> <538F18B6.7070102@ti.com> Date: Thu, 5 Jun 2014 01:30:40 +0300 Message-ID: Subject: Re: [PATCH V2 2/2] power: twl4030_charger: attempt to power off in case of critical events From: Grazvydas Ignotas To: Nishanth Menon Cc: dbaryshkov@gmail.com, Tony Lindgren , "linux-kernel@vger.kernel.org" , Felipe Balbi , "linux-omap@vger.kernel.org" , dwmw2@infradead.org, "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 4, 2014 at 4:01 PM, Nishanth Menon wrote: > On 06/04/2014 05:04 AM, Grazvydas Ignotas wrote: >> On Thu, May 29, 2014 at 12:46 AM, Nishanth Menon wrote: >>> Attempt to power off in case of critical events such as battery removal, >>> over voltage events. >>> >>> There is no guarentee that we'd be in a safe scenario here, but the very >>> least we can try to do is to power off the device to prevent damage to >>> the system instead of just printing a message and hoping for the best. >> >> At least "battery temperature out of range" does seem to happen quite >> often while charging on hot summer day. I'd prefer my pandora to not >> shutdown in such case, it could just stop charging instead. > Yeah, We could call > twl4030_charger_enable_ac(false); > twl4030_charger_enable_usb(bci, false); > > But then, is that sufficient? > From the TRM: > 7.5.8 Battery Temperature Out-of-Range Detection > Battery temperature out-of-range detection detects whether the battery > temperature is within a specific > range. Detection is possible for two temperature ranges. When the > battery temperature is not in the > 2–50°C range or is in the 3–43°C range, the TBATOR1 and TBATOR2 status > bits rise and an interrupt is > generated. > This MADC monitoring function can be enabled by writing to the > TBATOR1EN (BCIMFEN2[3]) and > TBATOR2EN (BCIMFEN2[1]) fields. > > Battery pack at high temperature is a risk, no? and it may not be just > charger that might be causing such a condition. Is'nt it safer to shut > the device down in such a case? I don't know, so far nobody has complained about the battery exploding and anybody getting hurt, but it would make the device unusable for people in hot climates. From what I remember the automatic charge is stopped automatically on this condition, as some people complained they couldn't charge their device and saw these messages in dmesg. I guess mainline could choose the safer option and shutdown, no strong opinion about this. -- Gražvydas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/