From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: [PATCH] ACPI/sbshc: Add 5us delay to fix SBS hang on MacBook Date: Mon, 18 May 2015 10:20:33 +0800 Message-ID: <55594C71.9060402@fnarfbargle.com> References: <20150424012530.GA16763@localhost> <4435249.leKkNHm9IZ@vostro.rjw.lan> <20150429202140.GB25904@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ns3.fnarfbargle.com ([103.4.17.7]:38986 "EHLO ns3.fnarfbargle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751051AbbERChk (ORCPT ); Sun, 17 May 2015 22:37:40 -0400 In-Reply-To: <20150429202140.GB25904@localhost> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Chris Bainbridge Cc: linux-acpi@vger.kernel.org On 30/04/15 04:21, Chris Bainbridge wrote: > > Supporting _OSI("Darwin") caused the MacBook firmware to expose the SBS, > resulting in intermittent hangs of several minutes on boot, and failure > to detect or report the battery. Fix this by adding a 5us delay to the > start of each SMBUS transaction. This timing is the result of > experimentation - hangs were observed with 3us but never with 5us. G'day Chris, Using 4.1-rc3 (whatever git head was from a couple of days ago) I've still been seeing ACPI lockups on my Macbook Pro (11,1). It appears to take a couple of suspend/resume cycles but seems to happen within 24 hours of booting whereas before this patch it was easy to hit. As a test (and I do wonder if it'll lock up after I press send on this E-mail) I upped the delay to 10us and I've now been up for 1 day, 17:23 with the battery still responding to polling. To make it easier to reproduce, I've been running a script that polls the battery every 60 seconds. I figure I'll let it go for another couple of days, but I wanted to put this out there in case anyone else is seeing lockups after a longer period of uptime. The symptoms are the ACPI command just hangs as does 'cat /sys/class/power_supply/BAT0/status'. From there I can't suspend as the tasks can't be frozen and I just end up hard booting the machine. I've removed Len & Rafael from the cc. Regards, Brad