From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: RE: [PATCH v2 1/9] omap4: powerdomain: Add supported INACTIVE power state Date: Mon, 7 Feb 2011 12:33:37 +0530 Message-ID: <9cb5f3c283cc93d27be0c727f6f3bafa@mail.gmail.com> References: <1296813544-25170-1-git-send-email-santosh.shilimkar@ti.com> <1296813544-25170-2-git-send-email-santosh.shilimkar@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from na3sys009aog112.obsmtp.com ([74.125.149.207]:53017 "EHLO na3sys009aog112.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752239Ab1BGHDj (ORCPT ); Mon, 7 Feb 2011 02:03:39 -0500 Received: by mail-iw0-f173.google.com with SMTP id 10so4749452iwc.32 for ; Sun, 06 Feb 2011 23:03:39 -0800 (PST) In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Paul Walmsley Cc: linux-omap@vger.kernel.org, Kevin Hilman , Benoit Cousson , Rajendra Nayak , linux-arm-kernel@lists.infradead.org > -----Original Message----- > From: Paul Walmsley [mailto:paul@pwsan.com] > Sent: Monday, February 07, 2011 2:12 AM > To: Santosh Shilimkar > Cc: linux-omap@vger.kernel.org; khilman@ti.com; b-cousson@ti.com; > rnayak@ti.com; linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH v2 1/9] omap4: powerdomain: Add supported > INACTIVE power state > > Hi > > On Fri, 4 Feb 2011, Santosh Shilimkar wrote: > > > On OMAP4, one can explicitly program INACTIVE as the power state > of > > the logic area inside the power domain. Techincally PD state > programmed > > to ON and if all the clock domains within the PD are idled, is > equivalent > > tp PD programmed to INACTIVE and all the clock domains within the > PD are > > idled. There won't be any power difference in above two. > > > > This patch adds the support to allow power domain INACTIVE > programming > > which is supported on OMAP4. > > > > The powerdomain autogen script is updated accordingly. > > Continuing the discussion here: > > http://www.mail-archive.com/linux- > omap@vger.kernel.org/msg43509.html > > 1. It appears that the OMAP4 powerdomain ON-ACTIVE state is a new > state > for OMAP4, and does not exist as such on previous chips (unless the > PRM_VOLTCTRL.AUTO_* bits are all disabled) > Actually it's not new state but more of convention change. ON-ACTIVE is like ON in OMAP3. > 2. It also appears that the OMAP4 powerdomain ON-INACTIVE state > is equivalent to the OMAP3 powerdomain ON state (again, assuming > that the > PRM_VOLTCTRL.AUTO_SLEEP bit is set on OMAP3). > This is correct. > Could you please comment on whether these statements are true or > false? > Just to summarise my undertsnaing of this here. On OMAP3 too, we had possibility of being in a one of the Two state when programmed to PD ON state. ON-ACTIVE or ON-INACTIVE. The PD status registers just says INACTIVE or ON based on the clodomains states within PD. On OMAP4, the difference is we do have a way to program the PD state explicitly as ON or INACTIVE. Regards, Santosh