From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DCF40C43A1D for ; Thu, 12 Jul 2018 12:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8648D20875 for ; Thu, 12 Jul 2018 12:41:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="nz1Is7rr"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="mI/4plUU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8648D20875 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732283AbeGLMvK (ORCPT ); Thu, 12 Jul 2018 08:51:10 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:44858 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726695AbeGLMvK (ORCPT ); Thu, 12 Jul 2018 08:51:10 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 8173360B10; Thu, 12 Jul 2018 12:41:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1531399305; bh=DTinPSsSGzlPAtJq/Fabe6YFPFlRfPRGQXU9TXwYoQ4=; h=In-Reply-To:References:From:Date:Subject:To:Cc:From; b=nz1Is7rrFUUtSNIV3oUvWscWmhtTxvd41qYNk0OiMwAvTitKp/JvZCUo39TFizmwH WvSGogBmr+rEAHh3a0i6GtydWT1xc6vdDcY8HVWWUMhwleUjYYOoxDGFwqOPIFcOM4 ht8EChlujvZIpvODxDTCscd0QpcUiS3AR+9g7d80= Received: from mail-qt0-f170.google.com (mail-qt0-f170.google.com [209.85.216.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: vivek.gautam@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id B7B3760B77; Thu, 12 Jul 2018 12:41:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1531399303; bh=DTinPSsSGzlPAtJq/Fabe6YFPFlRfPRGQXU9TXwYoQ4=; h=In-Reply-To:References:From:Date:Subject:To:Cc:From; b=mI/4plUUnBGVd5W1vBdMbJlxhGv3dLsOasz3+N3XTlQgocGGffSdghF+pbCbZ7r6f x2fkGpsALfXx+O7r3qqpeiY/e3rIyrHHLmgCl6dIxyFhU8v+QKiVw/o+sb+x+KshSq C2Y5d7UCaum7mggIm4dmYcLUR+dSuNuidCpdhG+0= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B7B3760B77 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vivek.gautam@codeaurora.org Received: by mail-qt0-f170.google.com with SMTP id q12-v6so23882794qtp.6; Thu, 12 Jul 2018 05:41:43 -0700 (PDT) X-Gm-Message-State: AOUpUlHxooB+7ZOPsWNPLPvRg4rrduPXlPFXIW9vSccqXYnrm6assgHd bFOnrb6R3t5XJuG/6GqWXpOSuoey2+otrBwGvRs= X-Google-Smtp-Source: AAOMgped+vtvPIsBOsw759o+yl4tRMMgUbO+1Wjab1eEn8UGSOTu6MySC8BQiTQWs9QaSvjsQMEk4+wNt74RbyeA12Y= X-Received: by 2002:ac8:3525:: with SMTP id y34-v6mr1538625qtb.241.1531399302909; Thu, 12 Jul 2018 05:41:42 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ac8:1082:0:0:0:0:0 with HTTP; Thu, 12 Jul 2018 05:41:42 -0700 (PDT) In-Reply-To: <741cc78b-59a7-5289-e42f-1511ebedb15d@codeaurora.org> References: <20180708173413.1965-1-vivek.gautam@codeaurora.org> <20180708173413.1965-4-vivek.gautam@codeaurora.org> <5179668.PHK6S3sxLu@aspire.rjw.lan> <741cc78b-59a7-5289-e42f-1511ebedb15d@codeaurora.org> From: Vivek Gautam Date: Thu, 12 Jul 2018 18:11:42 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v12 3/4] iommu/arm-smmu: Add the device_link between masters and smmu To: "Rafael J. Wysocki" Cc: "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , "robh+dt" , Mark Rutland , Robin Murphy , Will Deacon , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list , alex.williamson@redhat.com, Rob Clark , Linux PM , freedreno , sboyd@kernel.org, Tomasz Figa , Sricharan R , Marek Szyprowski , Archit Taneja , linux-arm-msm , Jordan Crouse , Lukas Wunner Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rafael, On Wed, Jul 11, 2018 at 4:06 PM, Vivek Gautam wrote: > Hi Rafael, > > > > On 7/11/2018 3:23 PM, Rafael J. Wysocki wrote: >> >> On Sunday, July 8, 2018 7:34:12 PM CEST Vivek Gautam wrote: >>> >>> From: Sricharan R >>> >>> Finally add the device link between the master device and >>> smmu, so that the smmu gets runtime enabled/disabled only when the >>> master needs it. This is done from add_device callback which gets >>> called once when the master is added to the smmu. >>> >>> Signed-off-by: Sricharan R >>> Signed-off-by: Vivek Gautam >>> Reviewed-by: Tomasz Figa >>> Cc: Rafael J. Wysocki >>> Cc: Lukas Wunner >>> --- >>> >>> - Change since v11 >>> * Replaced DL_FLAG_AUTOREMOVE flag with DL_FLAG_AUTOREMOVE_SUPPLIER. >>> >>> drivers/iommu/arm-smmu.c | 12 ++++++++++++ >>> 1 file changed, 12 insertions(+) >>> >>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >>> index 09265e206e2d..916cde4954d2 100644 >>> --- a/drivers/iommu/arm-smmu.c >>> +++ b/drivers/iommu/arm-smmu.c >>> @@ -1461,8 +1461,20 @@ static int arm_smmu_add_device(struct device *dev) >>> iommu_device_link(&smmu->iommu, dev); >>> + if (pm_runtime_enabled(smmu->dev) && >> >> Why does the creation of the link depend on whether or not runtime PM >> is enabled for the MMU device? > > > The main purpose of this device link is to handle the runtime PM > synchronization > between the supplier (iommu) and consumer (client devices, such as > GPU/display). > Moreover, the runtime pm is conditionally enabled for smmu devices that > support > such [1]. Is there something you would like me to modify in this patch? Best regards Vivek >> >> >> What about system-wide PM and system shutdown? Are they always guaranteed >> to happen in the right order without the link? > > > When there's no runtime PM, there's no clocks, and other resources to be > handled. > So, we don't need device link for system-wide PM and system shutdown to work > correctly. > That's the case with current arm-smmu driver. > Is it something that i am missing here? > > [1] https://lkml.org/lkml/2018/3/8/775 > > Thanks > Vivek >>> >>> + !device_link_add(dev, smmu->dev, >>> + DL_FLAG_PM_RUNTIME | >>> DL_FLAG_AUTOREMOVE_SUPPLIER)) { >>> + dev_err(smmu->dev, "Unable to add link to the consumer >>> %s\n", >>> + dev_name(dev)); >>> + ret = -ENODEV; >>> + goto out_unlink; >>> + } >>> + >>> return 0; >>> +out_unlink: >>> + iommu_device_unlink(&smmu->iommu, dev); >>> + arm_smmu_master_free_smes(fwspec); >>> out_cfg_free: >>> kfree(cfg); >>> out_free: >>> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation