From patchwork Fri Nov 17 18:05:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 839087 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ydmJ96XQhz9s7f for ; Sat, 18 Nov 2017 05:06:01 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161213AbdKQSFn (ORCPT ); Fri, 17 Nov 2017 13:05:43 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:53557 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161078AbdKQSFl (ORCPT ); Fri, 17 Nov 2017 13:05:41 -0500 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.84_2) (envelope-from ) id 1eFl1H-0000mZ-OK; Fri, 17 Nov 2017 19:05:39 +0100 From: Lucas Stach To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, kernel@pengutronix.de, patchwork-lst@pengutronix.de, Lukas Rusak , Chris Healy Subject: [PATCH 2/3] i2c: add runtime PM handling to core Date: Fri, 17 Nov 2017 19:05:38 +0100 Message-Id: <20171117180539.4984-3-l.stach@pengutronix.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171117180539.4984-1-l.stach@pengutronix.de> References: <20171117180539.4984-1-l.stach@pengutronix.de> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-i2c@vger.kernel.org Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This allows to simplify the drivers if they opt to use the runtime PM provided by the core. Even more importantly it allows to move the runtime PM handling out of the i2c bus lock. As runtime PM may need to take other locks itself (i.e. when manipulating clocks), holding the bus lock may lead to deadlocks, due to different lock ordering. Signed-off-by: Lucas Stach --- drivers/i2c/i2c-core-base.c | 18 ++++++++++++++++-- include/linux/i2c.h | 1 + 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 56e46581b84b..3c971711171c 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1931,11 +1931,19 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) } #endif + if (adap->auto_rpm) { + ret = pm_runtime_get_sync(adap->dev.parent); + if (ret < 0) + return ret; + } + if (in_atomic() || irqs_disabled()) { ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); - if (!ret) + if (!ret) { /* I2C activity is ongoing. */ - return -EAGAIN; + ret = -EAGAIN; + goto out_rpm; + } } else { i2c_lock_bus(adap, I2C_LOCK_SEGMENT); } @@ -1943,6 +1951,12 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) ret = __i2c_transfer(adap, msgs, num); i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); +out_rpm: + if (adap->auto_rpm) { + pm_runtime_mark_last_busy(adap->dev.parent); + pm_runtime_put_autosuspend(adap->dev.parent); + } + return ret; } else { dev_dbg(&adap->dev, "I2C level transfers not supported\n"); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index d501d3956f13..6bc3d1ed554e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -585,6 +585,7 @@ struct i2c_adapter { int nr; char name[48]; struct completion dev_released; + bool auto_rpm; /* runtime PM managed by core */ struct mutex userspace_clients_lock; struct list_head userspace_clients;