From patchwork Thu Nov 6 08:36:48 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 5240141 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 27FDFC11AC for ; Thu, 6 Nov 2014 08:38:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3C70A200DB for ; Thu, 6 Nov 2014 08:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C76920117 for ; Thu, 6 Nov 2014 08:38:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751934AbaKFIiZ (ORCPT ); Thu, 6 Nov 2014 03:38:25 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:64723 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751948AbaKFIhE (ORCPT ); Thu, 6 Nov 2014 03:37:04 -0500 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NEM005ZR02HGZ90@mailout3.w1.samsung.com>; Thu, 06 Nov 2014 08:39:54 +0000 (GMT) X-AuditID: cbfec7f5-b7f956d000005ed7-8e-545b332dacea Received: from eusync2.samsung.com ( [203.254.199.212]) by eucpsbgm2.samsung.com (EUCPMTA) with SMTP id 57.8B.24279.D233B545; Thu, 06 Nov 2014 08:37:01 +0000 (GMT) Received: from AMDC1943.digital.local ([106.116.151.171]) by eusync2.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0NEL00IEEZXIOS10@eusync2.samsung.com>; Thu, 06 Nov 2014 08:37:01 +0000 (GMT) From: Krzysztof Kozlowski To: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Russell King , Dan Williams , Vinod Koul , Ulf Hansson , Alan Stern , 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 , Krzysztof Kozlowski Subject: [PATCH v10 3/5] amba: Don't unprepare the clocks if device driver wants IRQ safe runtime PM Date: Thu, 06 Nov 2014 09:36:48 +0100 Message-id: <1415263010-7992-4-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1415263010-7992-1-git-send-email-k.kozlowski@samsung.com> References: <1415263010-7992-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrILMWRmVeSWpSXmKPExsVy+t/xK7q6xtEhBv1zlS02zljPajF96gVG i9VT/7JavH5haPF082Mmi7NNb9gtlkyez2rROXEJu8WsKXuZLC7vmsNm8bn3CKPF7cu8FmuP 3GW3ePcywuLuqaNsFmdOX2K1mPD7ApvF8bXhFi/79rM4CHu0NPeweczumMnqsXjPSyaPTas6 2TzuXNvD5rHkzSFWjy1X21k8Zt/9wejRt2UVo8eK1d/ZPT5vkvPY+/k3SwBPFJdNSmpOZllq kb5dAldGV88l5oKtQhXnX55gbWBs5O9i5OSQEDCRuNn/igXCFpO4cG89WxcjF4eQwFJGiXlX TkM5fUwS697sYQWpYhMwlti8fAlYQkTgOrNE9+N+sHZmgUVMEk1TFUFsYYE0iZ5TF5lAbBYB VYn2py+BGjg4eAXcJG5fiYbYJidx8thksJmcAu4Sv5Z8ACsXAipp/zqbfQIj7wJGhlWMoqml yQXFSem5RnrFibnFpXnpesn5uZsYIdHwdQfj0mNWhxgFOBiVeHgj2KNDhFgTy4orcw8xSnAw K4nwRugBhXhTEiurUovy44tKc1KLDzEycXBKNTAuqHk5ZUYH0wa1a1rfZh/f6x3wzlhuNvvy jZE3OZwTyrVan5YrNAmVWDN/CL+99N6Szp3veM6uP7LebM3SeKlJ+0NtDujfefvudYq7gMj8 p6ZFMssUv+pfy76cXsVSvJGr5twmrugV+97MbZhaUpoWVuUcd0b/1weJv7o/P+jdOXl3cUxN 4P3/SizFGYmGWsxFxYkAEjnOUmQCAAA= Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Ulf Hansson --- drivers/amba/bus.c | 17 +++++++++++++---- include/linux/amba/bus.h | 1 + 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 47bbdc1b5be3..356f906c6966 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -95,8 +95,14 @@ 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 = dev->power.irq_safe; + + if (pcdev->irq_safe) + clk_disable(pcdev->pclk); + else + clk_disable_unprepare(pcdev->pclk); + } return ret; } @@ -107,7 +113,10 @@ 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 +124,7 @@ 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 {