On 3 March 2014 17:02, Tomasz Figa <tomasz.figa@xxxxxxxxx> wrote: > On a number of platforms, devices are part of controllable power > domains, which need to be enabled before such devices can be accessed > and may be powered down when the device is idle to save some power. > This means that on systems that support power domain control using > generic power domains subsystem, it is necessary to add device to its > power domain before binding a driver to it and remove it from its power > domain after its driver is unbound to make sure that an unused device > does not affect power domain state. > > Since this is not limited to particular busses and specific > archs/platforms, it is more convenient to do the above directly in > driver core, just as done with pinctrl default configuration. This patch > adds necessary code to really_probe() and __device_release_driver() to > achieve this and maintain consistent stack-like ordering of operations > happening when binding and unbinding a driver. > > Signed-off-by: Tomasz Figa <tomasz.figa@xxxxxxxxx> This definitely makes sense to me! Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > --- > drivers/base/dd.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 0605176..78e5b36 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -23,6 +23,7 @@ > #include <linux/kthread.h> > #include <linux/wait.h> > #include <linux/async.h> > +#include <linux/pm_domain.h> > #include <linux/pm_runtime.h> > #include <linux/pinctrl/devinfo.h> > > @@ -273,6 +274,11 @@ static int really_probe(struct device *dev, struct device_driver *drv) > > dev->driver = drv; > > + /* If using genpd, bind power domain now before probing */ > + ret = genpd_bind_domain(dev); > + if (ret) > + goto probe_failed; > + > /* If using pinctrl, bind pins now before probing */ > ret = pinctrl_bind_pins(dev); > if (ret) > @@ -303,6 +309,7 @@ static int really_probe(struct device *dev, struct device_driver *drv) > probe_failed: > devres_release_all(dev); > driver_sysfs_remove(dev); > + genpd_unbind_domain(dev); > dev->driver = NULL; > dev_set_drvdata(dev, NULL); > > @@ -513,7 +520,7 @@ static void __device_release_driver(struct device *dev) > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > BUS_NOTIFY_UNBOUND_DRIVER, > dev); > - > + genpd_unbind_domain(dev); > } > } > > -- > 1.9.0 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
