Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933416AbbHXJU0 (ORCPT ); Mon, 24 Aug 2015 05:20:26 -0400 Received: from mga03.intel.com ([134.134.136.65]:29764 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933120AbbHXJUV (ORCPT ); Mon, 24 Aug 2015 05:20:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,736,1432623600"; d="scan'208";a="631047086" Date: Mon, 24 Aug 2015 14:52:30 +0530 From: Vinod Koul To: Jon Hunter Cc: Laxman Dewangan , Stephen Warren , Thierry Reding , Alexandre Courbot , dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Message-ID: <20150824092230.GI13546@localhost> References: <1439905755-25150-1-git-send-email-jonathanh@nvidia.com> <1439905755-25150-2-git-send-email-jonathanh@nvidia.com> <20150823141707.GB13546@localhost> <55DADA11.5040306@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55DADA11.5040306@nvidia.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1066 Lines: 30 On Mon, Aug 24, 2015 at 09:47:13AM +0100, Jon Hunter wrote: > > On 23/08/15 15:17, Vinod Koul wrote: > > On Tue, Aug 18, 2015 at 02:49:09PM +0100, Jon Hunter wrote: > > > >> @@ -1543,7 +1531,7 @@ static int tegra_dma_pm_suspend(struct device *dev) > >> int ret; > >> > >> /* Enable clock before accessing register */ > >> - ret = tegra_dma_runtime_resume(dev); > >> + ret = pm_runtime_get_sync(dev); > > > > why is this required ? > > Because the clock could be disabled when this function is called. This > function saves the DMA context so that if the context is lost during > suspend, it can be restored. Have you verified this? Coz my understanding is that when PM does suspend it will esnure you are runtime resume if runtime suspended and then will do suspend. So you do not need to do above -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/