From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH 0/2] omap_wdt: fix interface clock handling Date: Tue, 08 Mar 2011 09:08:11 -0800 Message-ID: <87bp1lv8uc.fsf@ti.com> References: <1299589583-22632-1-git-send-email-kalle.jokiniemi@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from na3sys009aog104.obsmtp.com ([74.125.149.73]:36038 "EHLO na3sys009aog104.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754587Ab1CHRIQ (ORCPT ); Tue, 8 Mar 2011 12:08:16 -0500 Received: by mail-pv0-f177.google.com with SMTP id 11so1047685pvh.8 for ; Tue, 08 Mar 2011 09:08:14 -0800 (PST) In-Reply-To: <1299589583-22632-1-git-send-email-kalle.jokiniemi@nokia.com> (Kalle Jokiniemi's message of "Tue, 8 Mar 2011 15:06:21 +0200") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kalle Jokiniemi Cc: linux-omap@vger.kernel.org, tony@atomide.com, ilkka.koskinen@nokia.com, wim@iguana.be Kalle Jokiniemi writes: > The runtime PM does not offer enough granularity to control > individual clocks separately as needed. Current pm implementation > of omap_wdt blocks the CORE power domain from idling in > OMAP SoC, as it keeps the interface clock of the watchdog always > on. This causes severe power leakage in devices where > the omap watchdog is in active use. The iclk remains active because it's in hardware-controlled auto-idle mode. I believe if you set the WDT hwmod to software-supported idle (OCPIF_SWSUP_IDLE), the runtime PM idle (which calls omap_device idle, then omap_hwmod_idle) should also gate the interface clock. > This patch set reverts the omap_wdt move to runtime_pm and > introduces a tight control of the interface clock in the driver > to only enable it when registers are accessed. The patch is > based on earlier patch by Atal Shargorodsky. > > If anyone has good suggestions how to fix this with runtime_pm, > feel free to propose patches. Otherwise I suggest we revert > back to something that works. Can you try with software-supported idle and just making the runtime PM calls more granular? Kevin > Tested with RX-51 S4.0 Macroboard, linux-omap-pm/pm branch and > MeeGo armv7l release. > > Kalle Jokiniemi (2): > Revert "OMAP: WDT: Use PM runtime APIs instead of clk FW APIs" > Watchdog: omap_wdt: fix interface clock handling > > drivers/watchdog/omap_wdt.c | 64 +++++++++++++++++++++++++++++++++++++------ > 1 files changed, 55 insertions(+), 9 deletions(-)