From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@ti.com (Kevin Hilman) Date: Wed, 30 May 2012 10:59:58 -0700 Subject: [PATCHv2 04/19] ARM: OMAP4: PM: save/restore all DPLL settings in OFF mode In-Reply-To: (Nishanth Menon's message of "Tue, 29 May 2012 14:46:55 -0500") 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> Message-ID: <87wr3t8s81.fsf@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: 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 wrote: >>>> Tero Kristo writes: >>>> > [...] >>>> - Rather than hooking into omap4_enter_lowpower(), should use >>>> ?the 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 here. >>> >>> 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. 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 sequence. > How do we plan to ensure the sequence is maintained in a notifier call > 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