Re: [PATCH] ARM: dts: am335x-bone* enable pmic-shutdown-controller

[Johan Hovold <johan@kernel.org>]

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 <matthijsvanduin@gmail.com>
> Tested-by: Matthijs van Duin <matthijsvanduin@gmail.com>
> Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Felipe Balbi <balbi@ti.com>
> Cc: Johan Hovold <johan@kernel.org>

This should go into stable as well:

Fixes: 672e2b147413 ("ARM: dts: am335x-boneblack: enable power off and
rtc wake up")
Cc: stable <stable@vger.kernel.org>	# 3.19
Acked-by: Johan Hovold <johan@kernel.org>

Thanks,
Johan