lkml.org 
[lkml]   [2014]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2 02/11] drivercore: Bind/unbind power domain on probe/remove
From
On 3 March 2014 17:02, Tomasz Figa <tomasz.figa@gmail.com> 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@gmail.com>

This definitely makes sense to me!

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

> ---
> 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
>


\
 
 \ /
  Last update: 2014-03-06 07:41    [W:0.244 / U:0.796 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site