From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753697AbaKDMxS (ORCPT ); Tue, 4 Nov 2014 07:53:18 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:46565 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753268AbaKDMxH (ORCPT ); Tue, 4 Nov 2014 07:53:07 -0500 X-AuditID: cbfec7f5-b7f956d000005ed7-d7-5458cc30a004 From: Krzysztof Kozlowski To: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Jonathan Corbet , Russell King , Dan Williams , Vinod Koul , Ulf Hansson , Alan Stern , Krzysztof Kozlowski , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Lars-Peter Clausen , Michal Simek Cc: Kevin Hilman , Laurent Pinchart , Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz Subject: [PATCH v9 2/4] amba: Don't unprepare the clocks if device driver wants IRQ safe runtime PM Date: Tue, 04 Nov 2014 13:52:48 +0100 Message-id: <1415105570-7871-3-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1415105570-7871-1-git-send-email-k.kozlowski@samsung.com> References: <1415105570-7871-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrDLMWRmVeSWpSXmKPExsVy+t/xq7oGZyJCDP4/VbbYOGM9q8WTA+2M FtOnXmC0WD31L6vF6xeGFk83P2ayONv0ht1iyeT5rBadE5ewW8yaspfJ4vKuOWwWn3uPMFrc vsxrsfbIXXaLdy8jLO6eOspmceb0JVaLCb8vsFkcXxtu8bJvP4uDiEdLcw+bx+yOmawei/e8 ZPLYtKqTzePOtT1sHov7JrN6LHlziNVjy9V2Fo/Zd38wevRtWcXosWL1d3aPz5vkPPZ+/s0S wBvFZZOSmpNZllqkb5fAlbHuaxNTwQ3RitfL/zI3MN4Q7GLk4JAQMJHoX+rbxcgJZIpJXLi3 nq2LkYtDSGApo0Rf7w9GCKePSeLgwlcsIFVsAsYSm5cvAasSEVjFIvFqz3Uwh1ngI6PEzdUb mUGqhAVSJb6fOgJmswioSrSc3s4IYvMKuEnsmPCDFWKfnMTJY5PBbE4Bd4mtG/exgdhCQDVv Hr1hm8DIu4CRYRWjaGppckFxUnqukV5xYm5xaV66XnJ+7iZGSIx83cG49JjVIUYBDkYlHt4V 8REhQqyJZcWVuYcYJTiYlUR4t50GCvGmJFZWpRblxxeV5qQWH2Jk4uCUamBseKN+dyNXcN87 n/bj4od+neG73alraPihz2TNmWeV8fJJ7nu46peFhVvu7Kt6PS/vbRbP4yuzzi7RubbYyF9l 5ipZpYu7Qut52vUCNog8n/yURcu9ceO0iQu+q5TePHj1Ds+KDrPQEK7KhQJX2AKlGbwDXJe5 Hs1x9GovDemfejYiS2jZsxQlluKMREMt5qLiRADDq2skbwIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The AMBA bus driver defines runtime Power Management functions which disable and unprepare AMBA bus clock. This is problematic for runtime PM because unpreparing a clock might sleep so it is not interrupt safe. However some drivers may want to implement runtime PM functions in interrupt-safe way (see pm_runtime_irq_safe()). In such case the AMBA bus driver should only disable/enable the clock in runtime suspend and resume callbacks. Detect the device driver behavior during runtime suspend. During runtime resume deal with clocks according to stored value. Signed-off-by: Krzysztof Kozlowski --- drivers/amba/bus.c | 24 ++++++++++++++++++++---- include/linux/amba/bus.h | 1 + 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 47bbdc1b5be3..27ec8882ec8e 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -85,6 +85,13 @@ static struct device_attribute amba_dev_attrs[] = { }; #ifdef CONFIG_PM + +#ifdef CONFIG_PM_RUNTIME +#define get_pm_runtime_irq_safe(dev) ((dev)->power.irq_safe) +#else +#define get_pm_runtime_irq_safe(dev) 1 +#endif + /* * Hooks to provide runtime PM of the pclk (bus clock). It is safe to * enable/disable the bus clock at runtime PM suspend/resume as this @@ -95,8 +102,14 @@ static int amba_pm_runtime_suspend(struct device *dev) struct amba_device *pcdev = to_amba_device(dev); int ret = pm_generic_runtime_suspend(dev); - if (ret == 0 && dev->driver) - clk_disable_unprepare(pcdev->pclk); + if (ret == 0 && dev->driver) { + pcdev->irq_safe = get_pm_runtime_irq_safe(dev); + + if (pcdev->irq_safe) + clk_disable(pcdev->pclk); + else + clk_disable_unprepare(pcdev->pclk); + } return ret; } @@ -107,7 +120,10 @@ static int amba_pm_runtime_resume(struct device *dev) int ret; if (dev->driver) { - ret = clk_prepare_enable(pcdev->pclk); + if (pcdev->irq_safe) + ret = clk_enable(pcdev->pclk); + else + ret = clk_prepare_enable(pcdev->pclk); /* Failure is probably fatal to the system, but... */ if (ret) return ret; @@ -115,7 +131,7 @@ static int amba_pm_runtime_resume(struct device *dev) return pm_generic_runtime_resume(dev); } -#endif +#endif /* CONFIG_PM */ static const struct dev_pm_ops amba_pm = { .suspend = pm_generic_suspend, diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h index ac02f9bd63dc..c4bae79851fb 100644 --- a/include/linux/amba/bus.h +++ b/include/linux/amba/bus.h @@ -32,6 +32,7 @@ struct amba_device { struct clk *pclk; unsigned int periphid; unsigned int irq[AMBA_NR_IRQS]; + unsigned int irq_safe:1; }; struct amba_driver { -- 1.9.1