From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226T7pOVtWsXk+o/n45s3wWTMg0ZAOIh733eQ/6ubUgsEap8nYF09Ao/tDShKK4+dafOle4n ARC-Seal: i=1; a=rsa-sha256; t=1517404185; cv=none; d=google.com; s=arc-20160816; b=eDQExzPE0vrR+WZfx3oDJU6bDBCJA0+f8ai0lY2snSAmTGg8EJ/pOHTYSLTuX200gp xmOAkrCNmbw2d2pM9QjAFK66K1uj86O9kQ8WQxDy3YAaislhtF735DK2pezJVeJjztZJ Qz84d15ge0gHM6mKIM84dvGutk7qvjSW5dVp/7WxTVAHMoGrxc6qPjRBCwLJcZJOBSb3 w4H4MGV+Bm2A5PGbhFJFhXhxMEVcCfQPkxe1jk1uw/ma+FxkvaVW2KclzM5//rdJ2Yyv EQ0M6zY1ve4xCwC18FkDql2g38gAljdlzU4SY8i7I/LcQx00KaBLMNxaCb0p3PFNExrX yAyg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :arc-authentication-results; bh=YzGf+UPkl3qvOL3F8+Gh4Ka2y/8HoSHu9/npNDt7Qt8=; b=yacfGzdjat8HH0Hl88BHTx4BSKXO2E/npASOwOgfS4PNbZzcmZ0XcRNP8echfp3fz3 SSig1ttQwPKgHKY+1EKqfGWp1ox3UtpRTPg08HznHll5HSIRY5uTkYcnW5M7qaMFy0vY A3GDge2kMDaziUk7ssk9oFeTftETIDHzJn/z/anR7qh1JGecv1BeVoHjMGdjFPDosY27 Qqbn4z4pmZTdbad8sIEqlsJ7tP7QPEdBaOor14os3YzJZp2KNGvAYuDJBYA6X9JF45Vq P1mvZlHajQO1Jw8lMLyRZyWN42KZlTKBGZ6Jp01Er4WsbcSKmfsgTQMPP6D0tjHbG+Si uIhA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of robin.murphy@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=robin.murphy@arm.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of robin.murphy@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=robin.murphy@arm.com Subject: Re: [PATCH v6 4/6] iommu/arm-smmu: Add the device_link between masters and smmu To: Vivek Gautam , alex.williamson@redhat.com, robh+dt@kernel.org, mark.rutland@arm.com, rjw@rjwysocki.net, will.deacon@arm.com, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, sboyd@codeaurora.org Cc: gregkh@linuxfoundation.org, sricharan@codeaurora.org, m.szyprowski@samsung.com, architt@codeaurora.org, linux-arm-msm@vger.kernel.org References: <1516362223-22946-1-git-send-email-vivek.gautam@codeaurora.org> <1516362223-22946-5-git-send-email-vivek.gautam@codeaurora.org> From: Robin Murphy Message-ID: <6b930150-cb81-b0a5-601c-16cb576c4341@arm.com> Date: Wed, 31 Jan 2018 13:09:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1516362223-22946-5-git-send-email-vivek.gautam@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590021073891800456?= X-GMAIL-MSGID: =?utf-8?q?1591113610859249510?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 19/01/18 11:43, 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. Don't we need to balance this with a device_link_del() in .remove_device (like exynos-iommu does)? Robin. > Signed-off-by: Sricharan R > --- > drivers/iommu/arm-smmu.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 95478bfb182c..33bbcfedb896 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1367,6 +1367,7 @@ static int arm_smmu_add_device(struct device *dev) > struct arm_smmu_device *smmu; > struct arm_smmu_master_cfg *cfg; > struct iommu_fwspec *fwspec = dev->iommu_fwspec; > + struct device_link *link; > int i, ret; > > if (using_legacy_binding) { > @@ -1428,6 +1429,16 @@ static int arm_smmu_add_device(struct device *dev) > > pm_runtime_put_sync(smmu->dev); > > + /* > + * Establish the link between smmu and master, so that the > + * smmu gets runtime enabled/disabled as per the master's > + * needs. > + */ > + link = device_link_add(dev, smmu->dev, DL_FLAG_PM_RUNTIME); > + if (!link) > + dev_warn(smmu->dev, "Unable to create device link between %s and %s\n", > + dev_name(smmu->dev), dev_name(dev)); > + > return 0; > > out_cfg_free: >