Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753312Ab3IIN7d (ORCPT ); Mon, 9 Sep 2013 09:59:33 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:58704 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752475Ab3IIN7a (ORCPT ); Mon, 9 Sep 2013 09:59:30 -0400 Date: Mon, 9 Sep 2013 09:59:26 -0400 From: Matt Porter To: Jonathan Austin Cc: Koen Kooi , Mark Rutland , "devicetree@vger.kernel.org" , "linux@arm.linux.org.uk" , Pawel Moll , "swarren@wwwdotorg.org" , "tony@atomide.com" , "ijc+devicetree@hellion.org.uk" , "linux-kernel@vger.kernel.org" , "rob.herring@calxeda.com" , "bcousson@baylibre.com" , "olof@lixom.net" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCHv3] ARM: OMAP2+: am335x-bone*: add DT for BeagleBone Black Message-ID: <20130909135924.GE10973@ohporter.com> References: <1378638746-10627-1-git-send-email-koen@dominion.thruhere.net> <20130909133059.GD10973@ohporter.com> <522DD251.2030607@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <522DD251.2030607@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3044 Lines: 77 On Mon, Sep 09, 2013 at 02:51:13PM +0100, Jonathan Austin wrote: > Hi Matt, > > On 09/09/13 14:31, Matt Porter wrote: > >On Sun, Sep 08, 2013 at 01:12:26PM +0200, Koen Kooi wrote: > >>The BeagleBone Black is basically a regular BeagleBone with eMMC and HDMI added, > >>so create a common dtsi both can use. > >> > >>IMPORTANT: booting the existing am335x-bone.dts will blow up the HDMI transceiver > >>after a dozen boots with an uSD card inserted because LDO will be at 3.3V instead > >>of 1.8. > >> > >>MMC support for AM335x still isn't in, so only the LDO change has been added. > >> > >>Signed-off-by: Koen Kooi > > > >Tested-by: Matt Porter > > > >Works fine for me on tip and 3.11. I did notice a regression in musb (worked > >on 3.11, now failing to probe but this is not related to your new dts as it > >happens on am335x-bone.dts too, assuming merge window volatility). One nit, > >git-am picked up a whitespace error on that extra line at EOF so you should > >trim that out. > > > >Only thing is...for a clear bug like this that will destroy hardware, it > >should be marked Cc: stable@vger.kernel.org to be picked up in stable. > > > > If I've understood Koen correctly then what he's saying is that if > you *were* to use the current (before this patch) am335x-bone.dts on > a Beagle Bone Black (which would be wrong, as that's not the board > you have...) then things would break. > > I don't see that this patch fixes that - as far as I can see, even > after the patch, using am335x-bone.dts with a Bone Black will risk > the damage? > > If so, I don't think this is a 'stable fix' kind of thing, as it > doesn't actually fix the problem? It fixes the problem by providing the correct dts for BBB which the vendor tree has had for sometime. In the absence of a specific dts for BBB, it appears everybody (TI and OMAP maintainers, included) has assumed that am335x-bone.dts is correct and safe. I'm sure there's plenty of systems represented in dts/* where you could cause damage by loading another dtb for a similar board from the same SoC family...it's a common risk if you get the wrong dtb with more-or-less arbitrary regulator settings. -Matt > > Koen - is there a way for a booting kernel to detect which board it > is on and avoid any potential damage if someone gives it the wrong > DT? > > Jonny > > >-Matt > > > >_______________________________________________ > >linux-arm-kernel mailing list > >linux-arm-kernel@lists.infradead.org > >http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/