From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH 1/2] OMAP3: cpuidle: prevent CORE power domain from going to RET or OFF when DSS is on Date: Fri, 04 Mar 2011 08:56:07 -0800 Message-ID: <87lj0uj048.fsf@ti.com> References: <20110301220833.32613.54669.stgit@twilight.localdomain> <20110301224918.32613.95176.stgit@twilight.localdomain> <87pqq7pz27.fsf@ti.com> <854C6400F5AA6644BA6FE7953F3E769B0380F12F@008-AM1MPN1-013.mgdnok.nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from na3sys009aog109.obsmtp.com ([74.125.149.201]:51443 "EHLO na3sys009aog109.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121Ab1CDQ4L (ORCPT ); Fri, 4 Mar 2011 11:56:11 -0500 Received: by mail-yw0-f44.google.com with SMTP id 6so916967ywi.3 for ; Fri, 04 Mar 2011 08:56:10 -0800 (PST) In-Reply-To: <854C6400F5AA6644BA6FE7953F3E769B0380F12F@008-AM1MPN1-013.mgdnok.nokia.com> (Tero Kristo's message of "Fri, 4 Mar 2011 08:14:07 +0000") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tero.Kristo@nokia.com Cc: paul@pwsan.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Hi Tero, writes: [...] >>> >>> + /* If DSS is active, prevent CORE RET/OFF */ >>> + dss_state = pwrdm_read_pwrst(dss_pd); >>> + if (dss_state == PWRDM_POWER_ON && >>> + core_next_state != PWRDM_POWER_ON) >>> + core_next_state = PWRDM_POWER_INACTIVE; >>> + >> >>Due to sleepdeps/autodeps, when this code runs, DSS powerdomain is >>always on. The result is that CORE is always set to INACTIVE. > > Now I recall that someone was asking about a patch similar to this > earlier, and had the same issue with DSS sleepdep collision. > > What is the reason for having the sleepdep for DSS powerdomain anyway? > At least I can't see any reason why the sleepdep for DSS should be > set. In my opinion it should be perfectly okay for DSS domain to idle > independently of MPU/CORE, as this is going to be better for power > consumption also. Agreed, but currently the sleepdeps with MPU are automatically managed (by clkdm autodeps and hwmod initiator deps.) Until we have merged a solution to more selectively enable sleepdeps (or remove them) $SUBJECT patch cannot be merged. Kevin