From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew McClintock Subject: Re: [PATCH 08/17] watchdog: qcom: configure BARK time in addition to BITE time Date: Thu, 24 Mar 2016 10:46:42 -0500 Message-ID: <19DAEEE1-1019-49FB-A921-4311F592A7EC@codeaurora.org> References: <1458770712-10880-1-git-send-email-mmcclint@codeaurora.org> <1458770712-10880-9-git-send-email-mmcclint@codeaurora.org> <20160323224226.GD18567@codeaurora.org> Mime-Version: 1.0 (Mac OS X Mail 9.2 \(3112\)) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:60780 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbcCXPqs convert rfc822-to-8bit (ORCPT ); Thu, 24 Mar 2016 11:46:48 -0400 In-Reply-To: <20160323224226.GD18567@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Stephen Boyd Cc: andy.gross@linaro.org, linux-arm-msm@vger.kernel.org, qca-upstream.external@qca.qualcomm.com, Wim Van Sebroeck , Guenter Roeck , "open list:WATCHDOG DEVICE DRIVERS" , open list On Mar 23, 2016, at 5:42 PM, Stephen Boyd wrote: >=20 > On 03/23, Matthew McClintock wrote: >> For certain parts and some versions of TZ, TZ will reset the chip >> when a BARK is triggered even though it was not configured here. So >> by default let's configure this BARK time as well. >>=20 >=20 > Why isn't TZ configuring the bark time to what it wants? I'm lost > why we have to do this for them. So it was done like this to ensure we had a valid upgrade. The bootload= er is using the watchdog to ensure the system is bootable and if not it= will revert back to the working images. Bottom line is, for some versions of TZ out there, if we enable watchdo= g coming out of boot the bark time is already configured by the boot lo= ader and TZ is configured to intercept this interrupt and do some regis= ter saving (for crashdump) and we end up getting a watchdog reset durin= g boot. It=E2=80=99s even a little more complex, because in order for the TZ to= save the registers you need to pad the BITE time a bit higher than the= BARK time, but I was leaving that for another day. -M-- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html