From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 12/13] ARM: dts: omap3-gta04: uart4 is not connected, so mark it "disabled" Date: Thu, 22 Jan 2015 13:40:53 -0800 Message-ID: <20150122214052.GY7718@atomide.com> References: <1421959099-28319-1-git-send-email-marek@goldelico.com> <1421959099-28319-13-git-send-email-marek@goldelico.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from smtp1.ore.mailhop.org ([54.68.34.165]:56406 "EHLO smtp1.ore.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754554AbbAVVoQ (ORCPT ); Thu, 22 Jan 2015 16:44:16 -0500 Content-Disposition: inline In-Reply-To: <1421959099-28319-13-git-send-email-marek@goldelico.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Marek Belisko Cc: bcousson@baylibre.com, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, hns@goldelico.com, neilb@suse.de, NeilBrown * Marek Belisko [150122 12:42]: > From: NeilBrown > > Signed-off-by: NeilBrown > --- > arch/arm/boot/dts/omap3-gta04.dtsi | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm/boot/dts/omap3-gta04.dtsi b/arch/arm/boot/dts/omap3-gta04.dtsi > index 228e79b..8d2b0a1 100644 > --- a/arch/arm/boot/dts/omap3-gta04.dtsi > +++ b/arch/arm/boot/dts/omap3-gta04.dtsi > @@ -357,6 +357,10 @@ > pinctrl-0 = <&uart3_pins>; > }; > > +&uart4 { > + status = "disabled"; > +}; > + This you probably want to avoid from PM point of view. Depending on bootloader state of uart4, Linux may or may not be able to hit any deeper power states. Marking something with status = "disabled" in dts causes the device entry not even to be created. That means hwmod won't be able to reset and idle this device during boot. The uart4 device is there for sure even if not muxed and in incomplete state. You may want to also check other places where you're using status = "disabled" for the same reasons. Regards, Tony