From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] I2C: Fix for suspend/resume issue in i2c-core Date: Mon, 30 Aug 2010 11:43:23 -0700 Message-ID: <87wrr83pro.fsf@deeprootsystems.com> References: <1283219414-8798-1-git-send-email-vishwanath.bs@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <1283219414-8798-1-git-send-email-vishwanath.bs-l0cyMroinI0@public.gmane.org> (Vishwanath BS's message of "Tue, 31 Aug 2010 07:20:14 +0530") Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Vishwanath BS Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Partha Basak , "Rafael J. Wysocki" , Ben Dooks , Mark Brown List-Id: linux-i2c@vger.kernel.org Vishwanath BS writes: > In current i2c core driver, pm_runtime_set_active call from i2c_device_pm_resume > is not balanced by pm_runtime_set_suspended call from i2c_device_pm_suspend. > pm_runtime_set_active called from resume path will increase the child_count of > the device's parent. However, matching pm_runtime_set_suspended is not called > in suspend routine because of which child_count of the device's parent > is not balanced, preventing the parent device to idle. > Issue has been fixed by adding pm_runtime_set_suspended call inside suspend > reoutine which will make sure that child_counts are balanced. > This fix has been tested on OMAP4430. > > Signed-off-by: Partha Basak > Signed-off-by: Vishwanath BS > > Cc: Rafael J. Wysocki > Cc: Kevin Hilman > Cc: Ben Dooks Also Cc'ing Mark Brown as original author of runtime PM for i2-core. Kevin > --- > drivers/i2c/i2c-core.c | 12 ++++++++++-- > 1 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index 6649176..3146bff > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -196,14 +196,22 @@ static int i2c_legacy_resume(struct device *dev) > static int i2c_device_pm_suspend(struct device *dev) > { > const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; > + int ret; > > if (pm_runtime_suspended(dev)) > return 0; > > if (pm) > - return pm->suspend ? pm->suspend(dev) : 0; > + ret = pm->suspend ? pm->suspend(dev) : 0; > + else > + ret = i2c_legacy_suspend(dev, PMSG_SUSPEND); > > - return i2c_legacy_suspend(dev, PMSG_SUSPEND); > + if (!ret) { > + pm_runtime_disable(dev); > + pm_runtime_set_suspended(dev); > + pm_runtime_enable(dev); > + } > + return ret; > } > > static int i2c_device_pm_resume(struct device *dev)