From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCHv2 04/19] ARM: OMAP4: PM: save/restore all DPLL settings in OFF mode Date: Wed, 30 May 2012 10:59:58 -0700 Message-ID: <87wr3t8s81.fsf@ti.com> References: <1336990730-26892-1-git-send-email-t-kristo@ti.com> <1336990730-26892-5-git-send-email-t-kristo@ti.com> <87d363928g.fsf@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from na3sys009aog125.obsmtp.com ([74.125.149.153]:53807 "EHLO na3sys009aog125.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757180Ab2E3SAO convert rfc822-to-8bit (ORCPT ); Wed, 30 May 2012 14:00:14 -0400 Received: by pbbrq2 with SMTP id rq2so299735pbb.34 for ; Wed, 30 May 2012 11:00:00 -0700 (PDT) In-Reply-To: (Nishanth Menon's message of "Tue, 29 May 2012 14:46:55 -0500") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Menon, Nishanth" Cc: "Shilimkar, Santosh" , paul@pwsan.com, Rajendra Nayak , Tero Kristo , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org "Menon, Nishanth" writes: > On Thu, May 17, 2012 at 3:52 AM, Shilimkar, Santosh > wrote: >> On Thu, May 17, 2012 at 12:34 PM, Shilimkar, Santosh >> wrote: >>> On Thu, May 17, 2012 at 4:12 AM, Kevin Hilman wrot= e: >>>> Tero Kristo writes: >>>> > [...] >>>> - Rather than hooking into omap4_enter_lowpower(), should use >>>> =C2=A0the cluster PM enter/exit notifier chain. >>>> >>> This is again specific to device OFF only and not related to CPU >>> cluster state as such. So I don't think notifiers should be used he= re. >>> >>> O.w even when we attempt just MPU OSWR C-state, all these functions= will >>> get called in notifier chain. >>> >> Just a thought, we can have a separate notifier chain for device OFF= =2E It can >> allow use to get rid of 'enable_off_mode" kind of flags and can be >> used by many drivers too. > > Like the overall idea, but one minor dumb concern might be sequencing > of notifiers > - OFF entry and restore needs things to be executed in a specific se= quence. > How do we plan to ensure the sequence is maintained in a notifier cal= l > chain? one > possible option might be a "priority" based scheme? Or just combine the events that need a specific sequence into single notifier callback function. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html