linux-kernel - Re: [PATCH] driver-core: platform: automatically mark wakeup devices

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Message-ID: <20160118061456.GA9099@dtor-ws>
Date:	Sun, 17 Jan 2016 22:14:56 -0800
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Rob Herring <robh@...nel.org>,
	Grant Likely <grant.likely@...aro.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Thierry Reding <treding@...dia.com>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>, linux-kernel@...r.kernel.org,
	"Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH] driver-core: platform: automatically mark wakeup devices

On Sun, Jan 17, 2016 at 09:11:25PM -0800, Greg Kroah-Hartman wrote:
> On Sun, Jan 17, 2016 at 06:11:38PM -0800, Dmitry Torokhov wrote:
> > When probing platform drivers let's check if corresponding devices have
> > "wakeup-source" property defined (either in device tree, ACPI, or static
> > platform properties) and automatically enable such devices as wakeup
> > sources for the system. This will help us standardize on the name for this
> > property and reduce amount of boilerplate code in the drivers.
> 
> How much boilerplate code can be removed?  Do you have an example patch
> of this removal for any drivers if we move this logic into the driver core?

Admittedly not a lot, a few lines. There is a couple of lines for
checking the property and calling device_init_wakeup() and also
sometimes clearing wakeup flag is the only thing that is left in
remove() method after converting to devm*. I am more interested in
standardizing on the property name and having wakeup flag cleared on
removal or probe failure, similarly how we do it for driver data in
device structure.

I do not have good patches in input at the moment as even though we are
using "wakeup-source" now lots if the drivers did not start with it and
so we have compatibility parsing still that we want to keep around. I
want the new drivers to use only this property though.

FWIW I2C bus code implements automatic parsing of this property as well
and I wonder if we want to do the same for SPI.

Thanks.

-- 
Dmitry