From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751086AbeE3J52 (ORCPT ); Wed, 30 May 2018 05:57:28 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38710 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714AbeE3J5V (ORCPT ); Wed, 30 May 2018 05:57:21 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 58A6660251 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: gregkh@linuxfoundation.org, rafael.j.wysocki@intel.com, lukas@wunner.de Cc: dmitry.torokhov@gmail.com, aspriel@gmail.com, robin.murphy@arm.com, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Vivek Gautam Subject: [PATCH 1/1] device core: Add flag to autoremove device link on supplier unbind Date: Wed, 30 May 2018 15:27:04 +0530 Message-Id: <20180530095704.5788-1-vivek.gautam@codeaurora.org> X-Mailer: git-send-email 2.16.1.72.g5be1f00a9a70 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using the device links without the consumers or suppliers maintaining pointers to these links, a flag can help in autoremoving the links on supplier driver unbind. We remove these links only when the supplier's link to its consumers has gone in DL_STATE_SUPPLIER_UNBIND state. Signed-off-by: Vivek Gautam Suggested-by: Lukas Wunner --- Lukas, as suggested in the thread [1] this change adds additional flag to autoremove device links on supplier unbind. For arm-smmu, we want to _not_ keep references to the device links added between arm-smmu, and consumer devices. Robin also pointed to [2] the need to autoremove the device link on supplier unbind rather than consumer unbind. [1] https://lkml.org/lkml/2018/3/14/390 [2] https://lkml.org/lkml/2018/5/21/381 drivers/base/core.c | 10 ++++++++++ include/linux/device.h | 2 ++ 2 files changed, 12 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index b610816eb887..52c7222bb3c4 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -490,6 +490,16 @@ void device_links_driver_cleanup(struct device *dev) WARN_ON(link->flags & DL_FLAG_AUTOREMOVE); WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND); + + /* + * autoremove the links between this @dev and its consumer + * devices that are not active, i.e. where the link state + * has moved to DL_STATE_SUPPLIER_UNBIND. + */ + if (link->status == DL_STATE_SUPPLIER_UNBIND && + link->flags & DL_FLAG_AUTOREMOVE_S) + kref_put(&link->kref, __device_link_del); + WRITE_ONCE(link->status, DL_STATE_DORMANT); } diff --git a/include/linux/device.h b/include/linux/device.h index 477956990f5e..6033bf58453d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -779,11 +779,13 @@ enum device_link_state { * AUTOREMOVE: Remove this link automatically on consumer driver unbind. * PM_RUNTIME: If set, the runtime PM framework will use this link. * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation. + * AUTOREMOVE_S: Remove this link automatically on supplier driver unbind. */ #define DL_FLAG_STATELESS BIT(0) #define DL_FLAG_AUTOREMOVE BIT(1) #define DL_FLAG_PM_RUNTIME BIT(2) #define DL_FLAG_RPM_ACTIVE BIT(3) +#define DL_FLAG_AUTOREMOVE_S BIT(4) /** * struct device_link - Device link representation. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation