From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752042AbaILO4h (ORCPT ); Fri, 12 Sep 2014 10:56:37 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:49192 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751283AbaILO4f (ORCPT ); Fri, 12 Sep 2014 10:56:35 -0400 X-AuditID: cbfec7f4-b7f156d0000063c7-b1-541309a024f8 From: Krzysztof Kozlowski To: Russell King , Dan Williams , Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Ulf Hansson , Grant Likely , Lars-Peter Clausen , Michal Simek Cc: Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Krzysztof Kozlowski Subject: [RFC PATCH v2 1/2] amba: Allow AMBA drivers to use their own runtime PM Date: Fri, 12 Sep 2014 16:56:18 +0200 Message-id: <1410533779-3310-2-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1410533779-3310-1-git-send-email-k.kozlowski@samsung.com> References: <1410533779-3310-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprNLMWRmVeSWpSXmKPExsVy+t/xy7oLOIVDDG6s07TYOGM9q8X0qRcY LVZP/ctqceDPDkaL1y8MLc42vWG3WDJ5PqvF5V1z2CxuX+a1WHvkLrvFu5cRFsfXhlu87NvP 4sDr0dLcw+axeM9LJo871/aweSx5c4jVo2/LKkaPz5vkPPZ+/s0SwB7FZZOSmpNZllqkb5fA lfHo4WGWgjm8FQvPLGNvYDzN1cXIySEhYCLR0HadHcIWk7hwbz1bFyMXh5DAUkaJZY8XsUM4 fUwSszfuB6tiEzCW2Lx8CViViMAlJolf916DVTELHGWUmN77lgmkSlggQOLj/DZGEJtFQFVi 9vdJYHFeATeJKVP/QO2Tkzh5bDIriM0p4C6xe+9EoHoOoHVuEh+3WU5g5F3AyLCKUTS1NLmg OCk911CvODG3uDQvXS85P3cTIyRAv+xgXHzM6hCjAAejEg8vxznBECHWxLLiytxDjBIczEoi vDdeCYUI8aYkVlalFuXHF5XmpBYfYmTi4JRqYMx/udVthsrR9UwCXp8X+MQKpnpNiGtZ87Vs Zv6iyUHTu0UVTsm8nSjDc1buYdyGD/37dHemvL4pyHmhNYqx5HLdIn6rm+zmAXOV5t6fw3Xc nWXTXN3/novW+RyaUKlX81b4X3tsvz/Hpmm3pb21JnsnH5h3dxtjb77/SX2F9fd/ztfmMrNj K1diKc5INNRiLipOBAAn9Jn3LgIAAA== 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()). If such driver implements its own runtime PM functions then assume it will handle the runtime PM completely and it will replace our clock handling. Signed-off-by: Krzysztof Kozlowski --- drivers/amba/bus.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 3cf61a127ee5..38461430b7cf 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -94,9 +94,18 @@ 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) + if (ret == 0 && dev->driver) { + /* + * If driver handles runtime suspend don't duplicate + * the work here. + */ + if (dev->driver->pm && dev->driver->pm->runtime_suspend) + goto out; + clk_disable_unprepare(pcdev->pclk); + } +out: return ret; } @@ -106,12 +115,16 @@ static int amba_pm_runtime_resume(struct device *dev) int ret; if (dev->driver) { + if (dev->driver->pm && dev->driver->pm->runtime_resume) + goto out; + ret = clk_prepare_enable(pcdev->pclk); /* Failure is probably fatal to the system, but... */ if (ret) return ret; } +out: return pm_generic_runtime_resume(dev); } #endif -- 1.9.1