Re: [RFC PATCH V2 3/8] genirq: Add runtime power management support for IRQ chips

From: Thomas Gleixner <tglx@linutronix.de>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Jon Hunter <jonathanh@nvidia.com>,
	Jason Cooper <jason@lakedaemon.net>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Jiang Liu <jiang.liu@linux.intel.com>,
	Stephen Warren <swarren@wwwdotorg.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Kevin Hilman <khilman@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Linus Walleij <linus.walleij@linaro.org>,
	Soren Brinkmann <soren.brinkmann@xilinx.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>
Subject: Re: [RFC PATCH V2 3/8] genirq: Add runtime power management support for IRQ chips
Date: Tue, 26 Jan 2016 18:17:26 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.11.1601261803410.3886@nanos> (raw)
In-Reply-To: <CAPDyKFoNcARZRZfXM1Rdn2PZqtnUdbfn1Fb4PzKZs_DKkxKtSw@mail.gmail.com>

On Fri, 22 Jan 2016, Ulf Hansson wrote:
> Here's a small collection of drivers that I easily picked up as
> candidates for using these new APIs.
> In principle, they would invoke these new APIs from their runtime PM callbacks.
> 
> drivers/spi/spi-atmel.c
> drivers/spi/spi-pl022.c
> drivers/i2c/busses/i2c-omap.c
> drivers/i2c/busses/i2c-nomadik.c
> drivers/i2c/busses/i2c-sh_mobile.c
> drivers/mmc/host/mtk-sd.c
> drivers/mmc/host/mmci.c

Instead of adding those calls to each driver, we can be smart and flag the
interrupt as AUTO_RUNTIME_SUSPEND or such.

So the runtime_pm core can handle it when invoking the
dev_pm_ops->runtime_suspend()/resume() callbacks.

Unfortunately the devres stuff is exceptionally bad to be used for this, but
with some surgery it should be doable.

Thanks,

	tglx