Re: [PATCH] PM / Domains: Change prototype for the ->attach_dev() callback

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Wed, Nov 05, 2014 at 02:43:31PM -0800, Kevin Hilman wrote:
> Dmitry Torokhov <dmitry.torokhov@gmail.com> writes:
> 
> > On Thu, Oct 30, 2014 at 01:38:30PM -0700, Kevin Hilman wrote:
> >> "Rafael J. Wysocki" <rjw@rjwysocki.net> writes:
> >> 
> >> > On Thursday, October 30, 2014 01:02:49 PM Ulf Hansson wrote:
> >> >> Convert the prototype to return and int. This is just an initial step,
> >> >> needed to support error handling.
> >> >> 
> >> >> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> >> 
> >> Acked-by: Kevin Hilman <khilman@linaro.org>
> >> 
> >> >> 
> >> >> This patch is intended as fix for 3.18 rc[n]. Why?
> >> >> 
> >> >> There are other SOC specific patches around that adds genpd support and which
> >> >> implements the ->attach_dev() callback. To prevent having an "atomic" patch
> >> >> during the next release cycle, let's change the prototype now instead.
> >> >> 
> >> >> Further patches will add the actual error handling in genpd and these can then
> >> >> be reviewed and tested thoroughly.
> >> >
> >> > So we have no users of ->attach_dev at the moment, right?
> >> 
> >> Not in mainline, but there are a couple getting ready to hit -next, so
> >> we wanted to fix this before they arrive so that adding the error
> >> handling will be easier.
> >
> > BTW, while we are at it, can we also pass the domain itself to
> > attach_dev() and detach_dev()? If anything it helps with debugging (you
> > can print domain name from the callbacks).
> 
> Agreed, and it makes it match the other callbacks (power_off, power_on)
> which currently take struct generic_pm_domain *domain.  
> 
> Updated version of $SUBJECT patch below.
> 
> Kevin
> 
> 
> ----- >8 ------
> From 353a62ffae2f9228142c8a2093108f9eda8dc6b4 Mon Sep 17 00:00:00 2001
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Date: Thu, 30 Oct 2014 13:02:49 +0100
> Subject: [PATCH] PM / Domains: Change prototype for the ->attach_dev()
>  callback
> 
> Convert the prototype to return and int. This is just an initial step,
> needed to support error handling.
> 
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> [khilman: added domain as parameter to callbacks, as suggested by Dmitry]
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Kevin Hilman <khilman@linaro.org>

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

> ---
>  drivers/base/power/domain.c | 4 ++--
>  include/linux/pm_domain.h   | 6 ++++--
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 40bc2f4072cc..b520687046d4 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1437,7 +1437,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
>  	spin_unlock_irq(&dev->power.lock);
>  
>  	if (genpd->attach_dev)
> -		genpd->attach_dev(dev);
> +		genpd->attach_dev(genpd, dev);

I guess as a followup we need to propagate the error returned by
genpd->attach_dev() here.

Thanks.

-- 
Dmitry