From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965495AbcJYGxY (ORCPT ); Tue, 25 Oct 2016 02:53:24 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:41980 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754908AbcJYGxW (ORCPT ); Tue, 25 Oct 2016 02:53:22 -0400 DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org 2E36D61B1E Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=sricharan@codeaurora.org From: "Sricharan" To: "'Marek Szyprowski'" , , , , Cc: "'Tomeu Vizoso'" , "'Bartlomiej Zolnierkiewicz'" , "'Greg Kroah-Hartman'" , "'Kevin Hilman'" , "'Rafael J. Wysocki'" , "'Tomasz Figa'" , "'Krzysztof Kozlowski'" , "'Inki Dae'" , "'Tobias Jakobi'" , "'Luis R. Rodriguez'" , "'Kukjin Kim'" , "'Mark Brown'" , "'Lukas Wunner'" References: <1476948173-21093-1-git-send-email-m.szyprowski@samsung.com> <1476948173-21093-8-git-send-email-m.szyprowski@samsung.com> <001e01d22d12$d2a4e990$77eebcb0$@codeaurora.org> <7a69ca4e-e276-1bdc-edf2-b881a91f820a@samsung.com> <004a01d22df2$45ecd450$d1c67cf0$@codeaurora.org> In-Reply-To: Subject: RE: [PATCH v5 7/7] iommu/exynos: Use device dependency links to control runtime pm Date: Tue, 25 Oct 2016 12:23:10 +0530 Message-ID: <009601d22e8c$786c7a80$69456f80$@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 15.0 Thread-Index: AQJ+uDLclmqDoXsyw4psny6anZSUigEQXHInAfnbw/MBDZHB4AH++rBSAW5TjN0BXPv8dZ8Ylqgg Content-Language: en-us Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marek, >>>>> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c >>>>> index 5e6d7bbf9b70..59b4f2ce4f5f 100644 >>>>> --- a/drivers/iommu/exynos-iommu.c >>>>> +++ b/drivers/iommu/exynos-iommu.c >>>>> @@ -781,10 +781,6 @@ static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain, >>>>> if (!has_sysmmu(dev) || owner->domain != iommu_domain) >>>>> return; >>>>> >>>>> - list_for_each_entry(data, &owner->controllers, owner_node) { >>>>> - pm_runtime_put_sync(data->sysmmu); >>>>> - } >>>>> - >>>>> mutex_lock(&owner->rpm_lock); >>>>> >>>>> list_for_each_entry(data, &owner->controllers, owner_node) { >>>>> @@ -848,10 +844,6 @@ static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain, >>>>> >>>>> mutex_unlock(&owner->rpm_lock); >>>>> >>>>> - list_for_each_entry(data, &owner->controllers, owner_node) { >>>>> - pm_runtime_get_sync(data->sysmmu); >>>>> - } >>>>> - >>>>> dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa\n", __func__, >>>>> &pagetable); >>>>> >>>>> @@ -1232,6 +1224,14 @@ static int exynos_iommu_of_xlate(struct device *dev, >>>>> >>>>> list_add_tail(&data->owner_node, &owner->controllers); >>>>> data->master = dev; >>>>> + >>>>> + /* >>>>> + * SYSMMU will be runtime activated via device link (dependency) to its >>>>> + * master device, so there are no direct calls to pm_runtime_get/put >>>>> + * in this driver. >>>>> + */ >>>>> + device_link_add(dev, data->sysmmu, DL_FLAG_PM_RUNTIME); >>>>> + >>>> So in the case of master with multiple sids, this would be called multiple times >>>> for the same master ? >>> I don't know what is "multiple sids" case, but if given SYSMMU master >>> device (supplier) >>> has multiple SYSMMU controllers (consumers), then links will be created >>> for each SYSMMU >>> controller. Please note that this code is based on vanilla v4.9-rc1, >>> which calls >>> of_xlate() callback only once for every iommu for given master device. >>> Your IOMMU >>> deferred probe patches change this, but I already posted a fix for >>> Exynos IOMMU driver >>> to handle such case. >> By multiple sids, i meant iommus = <&phandle sid1 sid2 .. sidn> case, >> so xlate would be called multiples for the same master without deferred >> probing also. But the fix that you showed on the other thread would work >> here as well or maybe if you dont have masters with multiple sids you wont >> have any issues as well. > >Exynos SYSMMU driver always use "#iommu-cells = <0>", so it doesn't support >multiple sids. However there is a case with 2 SYSMMU controllers attached >to the same master device: "iommus = <&sysmmu_mfc_l>, <&sysmmu_mfc_r>;". > with iommu-cells = <0> always, its ok. The case of 2 SYSMMU controllers that is shown above is fine, as anyways both the suppliers (symmu) needs to linked seperately. So it looks all fine. Regards, Sricharan