From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] I2C: Fix for suspend/resume issue in i2c-core Date: Tue, 31 Aug 2010 12:16:11 +0100 Message-ID: <20100831111611.GF20849@rakim.wolfsonmicro.main> References: <1283219414-8798-1-git-send-email-vishwanath.bs@ti.com> <87wrr83pro.fsf@deeprootsystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87wrr83pro.fsf@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org To: Kevin Hilman Cc: Vishwanath BS , linux-i2c@vger.kernel.org, linux-omap@vger.kernel.org, Partha Basak , "Rafael J. Wysocki" , Ben Dooks , Jean Delvare List-Id: linux-i2c@vger.kernel.org On Mon, Aug 30, 2010 at 11:43:23AM -0700, Kevin Hilman wrote: > 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. Also Jean Delvare who maintains the I2C core. To be honest Rafael did all the actual work here (and has since rewritten the code anyway). > > --- > > 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)