From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: Re: [PATCH] ARM: dts: am335x-bone* enable pmic-shutdown-controller Date: Wed, 13 May 2015 16:48:46 +0200 Message-ID: <20150513144846.GC6605@localhost> References: <1431525001-5747-1-git-send-email-robertcnelson@gmail.com> <20150513141658.GB6605@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150513141658.GB6605@localhost> Sender: linux-omap-owner@vger.kernel.org To: Robert Nelson Cc: tony@atomide.com, devicetree@vger.kernel.org, matthijsvanduin@gmail.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Felipe Balbi , Johan Hovold List-Id: devicetree@vger.kernel.org On Wed, May 13, 2015 at 04:16:58PM +0200, Johan Hovold wrote: > On Wed, May 13, 2015 at 08:50:01AM -0500, Robert Nelson wrote: > > Fixes: http://bugs.elinux.org/issues/143 > > > > Commit 672e2b147 which introduced proper shutdown chose to let the PMIC go into sleep-state (aka "RTC-only mode") rather than off-state. This was fine for rev A5 on which that patch was tested, but since then two changes have been made to the power supply scheme: > > > > (rev A6) enable of the 3v3b regulator moved from LDO2 to LDO4 (3v3a) > > side-effect: 3v3b rail remains on in sleep-mode (also in off-mode when battery-powered) > > > > (rev A6A) am335x vdds supply moved from LDO3 to LDO1 > > side-effect: vdds remains supplied in sleep-mode > > > > As a result heavy leakage occurs from vdds (directly) and 3v3b (via i/o pins) to the 3v3a. The amount of current depends on external connections, but for example leaving a serial console cable connected in this state resulted in serious violation of am335x absolute maximum ratings, with potential for hardware damage. > > > > Reported-by: Matthijs van Duin > > Tested-by: Matthijs van Duin > > Signed-off-by: Robert Nelson > > Cc: Tony Lindgren > > Cc: Felipe Balbi > > Cc: Johan Hovold > > This should go into stable as well: > > Fixes: 672e2b147413 ("ARM: dts: am335x-boneblack: enable power off and > rtc wake up") > Cc: stable # 3.19 > Acked-by: Johan Hovold By the way, perhaps you should add a comment in the tps node explaining why ti,pmic-shutdown-controller must not be disabled (on what revisions of hardware) as well? Johan