From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonyoung Shim Subject: Re: [PATCH 4/7] Exynos: add support for 'domain-always-on' property Date: Wed, 02 Jul 2014 16:28:41 +0900 Message-ID: <53B3B4A9.6060307@samsung.com> References: <1404202211-15788-1-git-send-email-m.szyprowski@samsung.com> <1404202211-15788-5-git-send-email-m.szyprowski@samsung.com> <53B276BE.2090509@gmx.net> <53B27AA3.5030000@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:57403 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750757AbaGBH2m (ORCPT ); Wed, 2 Jul 2014 03:28:42 -0400 Received: from epcpsbgr2.samsung.com (u142.gpu120.samsung.co.kr [203.254.230.142]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N8200BEGQ3ME390@mailout3.samsung.com> for linux-samsung-soc@vger.kernel.org; Wed, 02 Jul 2014 16:28:34 +0900 (KST) In-reply-to: <53B27AA3.5030000@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Marek Szyprowski , Tobias Jakobi , linux-samsung-soc@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: Tomasz Stanislawski , Kukjin Kim , Daniel Drake , Andrzej Hajda Hi Marek, On 07/01/2014 06:08 PM, Marek Szyprowski wrote: > Hello, > > On 2014-07-01 10:52, Tobias Jakobi wrote: >> Hello Marek, >> >> I think you had a similar patch in the tizen tree, but according to >> Tomasz Figa, it was considered a hack. I don't quite see how this is >> different. >> >> Also, if I have been following the discussion correctly, then the >> powerdomain issue essentially is about the question which SoC block >> needs the LCD0 domain and how the proper power on/off sequences should >> look like. >> >> At least the mixer power issue, which I pointed out some time ago, seems >> to be deal with now: >> https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/commit/?h=exynos-drm-next&id=381be025ac1a6dc8efebdf146ced0d4a6007f77b >> > > Well, that patch solves power on/off sequence issue with mixer and hdmi, > but it didn't solve the issue with additional managing of power domain > on/off. You can check that if you remove always on property, system will > freeze when hdmi cable is connected for the second time. I've > investigated > it for some time, but right now I didn't find any 100% reliable solution > other than keeping the power domain enabled all the time. At least for > now, this patch lets you use HDMI without any stability issues. > > I've only found that there are still at least 2 issues with power > domains. > One is Mixer/Video Processor dependency on LCD0 domain, second is the > proper To express dependency of LCD0 domain and TV domain, how about make master and slave hierarchy between the pm domains using pm_genpd_add_subdomain? > power on/off sequence of HDMI/Mixer and TV domain. Forcing both > domains to > 'always on' workarounds both issues for now. Right now I have no better > idea. > > Later, once the proper sequence is found we can remove those properties > from Odroid DTS. > > Best regards