From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751788AbeEQJU4 (ORCPT ); Thu, 17 May 2018 05:20:56 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35478 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751231AbeEQJUy (ORCPT ); Thu, 17 May 2018 05:20:54 -0400 X-Google-Smtp-Source: AB8JxZpgdHy5TsPWX0b9x+t0/VRtwX4jFGDbH8LwSYow7CSS8usElpk24T4g9QzyMle0xsMqv2/7zA== Subject: Re: [PATCH] dmaengine: qcom: bam_dma: check if the runtime pm enabled To: Vinod Cc: agross@codeaurora.org, dmaengine@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20180514161852.9620-1-srinivas.kandagatla@linaro.org> <20180517052107.GT13271@vkoul-mobl> From: Srinivas Kandagatla Message-ID: <2136d6a5-c039-d319-0d32-b0f6ef81e4e0@linaro.org> Date: Thu, 17 May 2018 10:20:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20180517052107.GT13271@vkoul-mobl> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/05/18 06:21, Vinod wrote: > On 14-05-18, 17:18, Srinivas Kandagatla wrote: >> Disabling pm runtime at probe is not sufficient to get BAM working >> on remotely controller instances. pm_runtime_get_sync() would return >> -EACCES in such cases. >> So check if runtime pm is enabled before returning error from bam functions. >> >> Fixes: 5b4a68952a89 ("dmaengine: qcom: bam_dma: disable runtime pm on remote controlled") >> Signed-off-by: Srinivas Kandagatla >> --- >> drivers/dma/qcom/bam_dma.c | 10 +++++----- >> 1 file changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c >> index d29275b97e84..5f4babebc508 100644 >> --- a/drivers/dma/qcom/bam_dma.c >> +++ b/drivers/dma/qcom/bam_dma.c >> @@ -540,7 +540,7 @@ static void bam_free_chan(struct dma_chan *chan) >> int ret; >> >> ret = pm_runtime_get_sync(bdev->dev); >> - if (ret < 0) >> + if (pm_runtime_enabled(bdev->dev) && ret < 0) > > would it make sense to first check enabled and do _get_sync() > Both of them check the disable_depth, however doing it the way you suggested would avoid some additional calls. > if (pm_runtime_enabled()) { > ret = pm_runtime_get_sync() { > ... > } > } sound like good idea! > Just noticed that some of the drivers use: err = pm_runtime_get_sync(dev); if (err < 0 && err !=-EACCES) return; others warp up this into local function. Will send a v2! thanks, srini > thus making clear in code that we do calls only when it is enabled. Also you can > add a local macro for this code and use that rather than copy pasting :) >