From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753292AbdLHMbP (ORCPT ); Fri, 8 Dec 2017 07:31:15 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:43572 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546AbdLHMbK (ORCPT ); Fri, 8 Dec 2017 07:31:10 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C025C60218 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vivek.gautam@codeaurora.org From: Vivek Gautam To: rjw@rjwysocki.net, len.brown@intel.com, pavel@ucw.cz, gregkh@linuxfoundation.org Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, sboyd@codeaurora.org, robdclark@gmail.com, robin.murphy@arm.com, will.deacon@arm.com, linux-arm-msm@vger.kernel.org, Vivek Gautam Subject: [PATCH 1/1] base: power: runtime: Export pm_runtime_get/put_suppliers Date: Fri, 8 Dec 2017 18:00:47 +0530 Message-Id: <1512736247-16538-1-git-send-email-vivek.gautam@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The device link allows the pm framework to tie the supplier and consumer. So, whenever the consumer is powered-on, the supplier is powered-on first. There are however cases in which the consumer wants to power-on the supplier, but not itself. E.g., A Graphics or multimedia driver wants to power-on the SMMU to unmap a buffer and finish the TLB operations without powering on itself. Some of these unmap requests are coming from the user space when the controller itself is not powered-up, and it can be huge penalty in terms of power and latency to power-up the graphics/mm controllers. There can be an argument that the supplier should handle this case on its own and there should not be a need for the consumer to power-on the supplier. But as discussed on the thread [1] about ARM-SMMU runtime pm, we don't want to introduce runtime pm calls in atomic paths, such as in arm_smmu_unmap. [1] https://patchwork.kernel.org/patch/9827825/ Signed-off-by: Vivek Gautam --- drivers/base/power/runtime.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 027d159ac381..af169304ca13 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1578,6 +1578,7 @@ void pm_runtime_get_suppliers(struct device *dev) device_links_read_unlock(idx); } +EXPORT_SYMBOL_GPL(pm_runtime_get_suppliers); /** * pm_runtime_put_suppliers - Drop references to supplier devices. @@ -1596,6 +1597,7 @@ void pm_runtime_put_suppliers(struct device *dev) device_links_read_unlock(idx); } +EXPORT_SYMBOL_GPL(pm_runtime_put_suppliers); void pm_runtime_new_link(struct device *dev) { -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation