From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 13/25] OMAP4: PM: Add WakeupGen module as OMAP gic_arch_extn Date: Wed, 14 Sep 2011 12:04:33 -0700 Message-ID: <20110914190433.GP24252@atomide.com> References: <1315144466-9395-1-git-send-email-santosh.shilimkar@ti.com> <1315144466-9395-14-git-send-email-santosh.shilimkar@ti.com> <20110913203616.GG24252@atomide.com> <20110914152116.GM24252@atomide.com> <4E70DB33.5070501@ti.com> <20110914170803.GN24252@atomide.com> <4E70E0CC.80300@ti.com> <20110914171800.GO24252@atomide.com> <4E70E2DE.2030006@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-04-ewr.mailhop.org ([204.13.248.74]:36219 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932462Ab1INTEh (ORCPT ); Wed, 14 Sep 2011 15:04:37 -0400 Content-Disposition: inline In-Reply-To: <4E70E2DE.2030006@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Santosh Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, khilman@ti.com, rnayak@ti.com, "Woodruff, Richard" * Santosh [110914 09:49]: > On Wednesday 14 September 2011 10:48 PM, Tony Lindgren wrote: > >* Santosh [110914 09:40]: > >>On Wednesday 14 September 2011 10:38 PM, Tony Lindgren wrote: > >>>* Santosh [110914 09:16]: > >>> > >>>Thanks for the clarification. It seems to me the spec is most likely > >>>wrong as we've had the GIC working for over two years now without > >>>doing anything with the wakeup gen registers :) > >>> > >>It's working because CPU clockdomain are never put under HW > >>supervised mode and they are kept in force wakeup. Clock-domain > >>never idles on mainline code. PM series will put the clock-domains > >>under HW supervison as needed to achieve any low power states and > >>then all sorts of corner cases will come out. > > > >But again the wakeup gen triggers only do something when hitting > >idle. There should be no use for them during runtime, right? > > > You missed my point in the description. Clockdomain inactive > doesn't depend on idle or WFI execution. Under HW supervison > CPU clock domain can get into inactive when CPU is stalled and > waiting for a read response from slow interconnect. Ah OK. If it's needed during runtime too then that explains why the registers need to be kept in sync. > One thing for sure. Designers has chosen a wrong name to this > IP. Wakeugen apears like needed only for low power wakeup which > not seems to be entirely correct as per specs Yes it's not obvious reading the TRM either. Maybe add some comment about that to the patch? Regards, Tony