linux-kernel - Re: [PATCH] i8042 / PM: Allow PC keyboard to wake up from suspend-to-idle

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Date:	Tue, 10 Mar 2015 00:08:43 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Kristen Carlson Accardi <kristen@...ux.intel.com>,
	Linux PM list <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-input@...r.kernel.org
Subject: Re: [PATCH] i8042 / PM: Allow PC keyboard to wake up from suspend-to-idle

On Monday, March 09, 2015 11:41:12 PM Rafael J. Wysocki wrote:
> On Monday, March 09, 2015 11:00:04 AM Dmitry Torokhov wrote:
> > Hi Rafael,
> > 
> > On Mon, Mar 09, 2015 at 04:19:50PM +0100, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > > 
> > > If they keyboard interrupt is registered, mark the i8042 platform
> > > device as wakeup-capable and check the user space wakeup setting in
> > > i8042_pm_suspend() and i8042_pm_resume() to enable or disable,
> > > respectively, the keyboard interrupt to wake up the system.
> > > 
> > > This makes it possible to use the PC keyboard to wake up the system
> > > from suspend-to-idle after writing "enabled" to the i8042 device's
> > > power/wakeup sysfs attribute.
> > 
> > Why do we do that for KBD but not AUX port? Should we mark individual
> > serio port be wakeup capable and not the whole i8042.
> 
> We can do that, but only after the port serio device has been registered.
> 
> I guess I can add code for that to i8042_register_ports().  Let me try that.

Yeah, that works too.  And you're right that there's no reason to do that for
keyboard only.

Patch below.

Rafael


---
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Subject: i8042 / PM: Allow i8042 ports to wake up from suspend-to-idle

While registering serio device for i8042, mark them as wakeup-capable
and check their user space wakeup settings in i8042_pm_suspend() and
i8042_pm_resume() to enable or disable, respectively, their interrupts
to wake up the system.

This makes it possible to use the PC keyboard to wake up the system
from suspend-to-idle, among other things, after writing "enabled" to
the keyboard serio device's power/wakeup sysfs attribute.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/input/serio/i8042.c |   28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/input/serio/i8042.c
===================================================================
--- linux-pm.orig/drivers/input/serio/i8042.c
+++ linux-pm/drivers/input/serio/i8042.c
@@ -1162,13 +1162,32 @@ static int i8042_controller_resume(bool
 
 static int i8042_pm_suspend(struct device *dev)
 {
+	int i;
+
 	i8042_controller_reset(true);
 
+	/* Set up serio interrupts for system wakeup. */
+	for (i = 0; i < I8042_NUM_PORTS; i++) {
+		struct serio *serio = i8042_ports[i].serio;
+
+		if (serio && device_may_wakeup(&serio->dev))
+			enable_irq_wake(i8042_ports[i].irq);
+	}
+
 	return 0;
 }
 
 static int i8042_pm_resume(struct device *dev)
 {
+	int i;
+
+	for (i = 0; i < I8042_NUM_PORTS; i++) {
+		struct serio *serio = i8042_ports[i].serio;
+
+		if (serio && device_may_wakeup(&serio->dev))
+			disable_irq_wake(i8042_ports[i].irq);
+	}
+
 	/*
 	 * On resume from S2R we always try to reset the controller
 	 * to bring it in a sane state. (In case of S2D we expect
@@ -1300,13 +1319,16 @@ static void __init i8042_register_ports(
 	int i;
 
 	for (i = 0; i < I8042_NUM_PORTS; i++) {
-		if (i8042_ports[i].serio) {
+		struct serio *serio = i8042_ports[i].serio;
+
+		if (serio) {
 			printk(KERN_INFO "serio: %s at %#lx,%#lx irq %d\n",
-				i8042_ports[i].serio->name,
+				serio->name,
 				(unsigned long) I8042_DATA_REG,
 				(unsigned long) I8042_COMMAND_REG,
 				i8042_ports[i].irq);
-			serio_register_port(i8042_ports[i].serio);
+			serio_register_port(serio);
+			device_set_wakeup_capable(&serio->dev, true);
 		}
 	}
 }

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