linux-kernel - Re: [PATCH v5 02/11] i2c: omap: wakeup the controller during suspend() callback

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Date: Mon, 22 Apr 2024 14:44:23 -0500
From: Bjorn Helgaas <helgaas@...nel.org>
To: Thomas Richard <thomas.richard@...tlin.com>
Cc: Andi Shyti <andi.shyti@...nel.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Bartosz Golaszewski <brgl@...ev.pl>,
	Tony Lindgren <tony@...mide.com>,
	Aaro Koskinen <aaro.koskinen@....fi>,
	Janusz Krzysztofik <jmkrzyszt@...il.com>,
	Vignesh R <vigneshr@...com>, Peter Rosin <peda@...ntia.se>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kw@...ux.com>,
	Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
	Siddharth Vadapalli <s-vadapalli@...com>,
	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-omap@...r.kernel.org, linux-i2c@...r.kernel.org,
	linux-pci@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	gregory.clement@...tlin.com, theo.lebrun@...tlin.com,
	thomas.petazzoni@...tlin.com, u-kumar1@...com,
	Wolfram Sang <wsa+renesas@...g-engineering.com>
Subject: Re: [PATCH v5 02/11] i2c: omap: wakeup the controller during
 suspend() callback

On Mon, Apr 22, 2024 at 11:40:02AM +0200, Thomas Richard wrote:
> On 4/19/24 10:47, Andi Shyti wrote:
> > Hi Thomas,
> > 
> >> +static int omap_i2c_suspend(struct device *dev)
> >> +{
> >> +	/*
> >> +	 * If the controller is autosuspended, there is no way to wakeup it once
> >> +	 * runtime pm is disabled (in suspend_late()).
> >> +	 * But a device may need the controller up during suspend_noirq() or
> >> +	 * resume_noirq().
> >> +	 * Wakeup the controller while runtime pm is enabled, so it is available
> >> +	 * until its suspend_noirq(), and from resume_noirq().
> >> +	 */
> >> +	return pm_runtime_resume_and_get(dev);
> >> +}
> >> +
> >> +static int omap_i2c_resume(struct device *dev)
> >> +{
> >> +	pm_runtime_mark_last_busy(dev);
> >> +	pm_runtime_put_autosuspend(dev);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >>  static const struct dev_pm_ops omap_i2c_pm_ops = {
> >>  	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> >>  				      pm_runtime_force_resume)
> >> +	SET_SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume)
> > 
> > If you don't have CONFIG_PM_SLEEP, though, this doesn't compile.
> 
> Hello Andi,
> 
> Yes indeed, the __maybe_unused attribute is missing for
> omap_i2c_suspend() and omap_i2c_resume().

Isn't there a way to avoid having to use the __maybe_unused attribute?

E.g., use DEFINE_SIMPLE_DEV_PM_OPS() as is done by these:

  82f9cefadac4 ("serial: 8250_exar: switch to DEFINE_SIMPLE_DEV_PM_OPS()")
  f243df0a0be0 ("media: platform: rzg2l-cru: rzg2l-csi2: Switch to RUNTIME_PM_OPS()")
  6ccc22a5afcb ("net: ravb: Switch to SYSTEM_SLEEP_PM_OPS()/RUNTIME_PM_OPS() and pm_ptr()")

Bjorn