From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: Unable to boot mainline on snow chromebook since 3.15 Date: Mon, 08 Sep 2014 08:09:35 +0200 Message-ID: <540D481F.8030500@collabora.co.uk> References: <20140905115704.GO13515@arm.com> <20140905122232.GP13515@arm.com> <540C202E.2060009@collabora.co.uk> <540C7F5B.6070307@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:33340 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751982AbaIHGJm (ORCPT ); Mon, 8 Sep 2014 02:09:42 -0400 In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Doug Anderson , Tomasz Figa Cc: Will Deacon , "kgene.kim@samsung.com" , "olof@lixom.net" , "rahul.sharma@samsung.com" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , Mark Brown Hello Doug, On 09/08/2014 06:36 AM, Doug Anderson wrote: > > One (ugly?) solution would be to add a feature to your bootloader to > modify the device tree to mark regulators as "always-on". Since the > booloader gets to touch the device tree and the bootloader is involved > in communicating into about SimpleFB, it kinda makes sense. > I can't say I like to mark the regulators as always-on on the DT and that's why I copied the patch in the response instead of posting it as a proper patch but I think relying in the bootloaders to modify the DT is not better. IMHO U-boot should only modify the strictly necessary like the /chosen branch even though lately I've seen some attempts in the OMAP community to (ab)use U-Boot's fdt command to mangle the DT before passing to the kernel in order to support different Beagle Bone Black capes. Best regards, Javier From mboxrd@z Thu Jan 1 00:00:00 1970 From: javier.martinez@collabora.co.uk (Javier Martinez Canillas) Date: Mon, 08 Sep 2014 08:09:35 +0200 Subject: Unable to boot mainline on snow chromebook since 3.15 In-Reply-To: References: <20140905115704.GO13515@arm.com> <20140905122232.GP13515@arm.com> <540C202E.2060009@collabora.co.uk> <540C7F5B.6070307@gmail.com> Message-ID: <540D481F.8030500@collabora.co.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Doug, On 09/08/2014 06:36 AM, Doug Anderson wrote: > > One (ugly?) solution would be to add a feature to your bootloader to > modify the device tree to mark regulators as "always-on". Since the > booloader gets to touch the device tree and the bootloader is involved > in communicating into about SimpleFB, it kinda makes sense. > I can't say I like to mark the regulators as always-on on the DT and that's why I copied the patch in the response instead of posting it as a proper patch but I think relying in the bootloaders to modify the DT is not better. IMHO U-boot should only modify the strictly necessary like the /chosen branch even though lately I've seen some attempts in the OMAP community to (ab)use U-Boot's fdt command to mangle the DT before passing to the kernel in order to support different Beagle Bone Black capes. Best regards, Javier