Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754086AbbHXIrW (ORCPT ); Mon, 24 Aug 2015 04:47:22 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:5566 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753806AbbHXIrU (ORCPT ); Mon, 24 Aug 2015 04:47:20 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Mon, 24 Aug 2015 01:47:20 -0700 Message-ID: <55DADA11.5040306@nvidia.com> Date: Mon, 24 Aug 2015 09:47:13 +0100 From: Jon Hunter User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Vinod Koul CC: Laxman Dewangan , Stephen Warren , Thierry Reding , "Alexandre Courbot" , , , , Subject: Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage References: <1439905755-25150-1-git-send-email-jonathanh@nvidia.com> <1439905755-25150-2-git-send-email-jonathanh@nvidia.com> <20150823141707.GB13546@localhost> In-Reply-To: <20150823141707.GB13546@localhost> X-Originating-IP: [10.21.132.159] X-ClientProxiedBy: UKMAIL102.nvidia.com (10.26.138.15) To UKMAIL101.nvidia.com (10.26.138.13) Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 784 Lines: 25 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. Cheers Jon -- 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/