linux-kernel - [PATCH] Input: gpio-keys - fix un-responsive keys issue on hibernate exit

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Message-ID: <20241018-unresponsive-gpio-keys-hibernate-v1-1-12f5e9962054@quicinc.com>
Date: Fri, 18 Oct 2024 18:22:35 +0530
From: Kamal Wadhwa <quic_kamalw@...cinc.com>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>
CC: <linux-input@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        "Jishnu
 Prakash" <quic_jprakash@...cinc.com>,
        Rakesh Kota
	<quic_kotarake@...cinc.com>,
        <linux-arm-msm@...r.kernel.org>,
        Kamal Wadhwa
	<quic_kamalw@...cinc.com>
Subject: [PATCH] Input: gpio-keys - fix un-responsive keys issue on
 hibernate exit

GPIO IRQ setting may get reset during hibernate mode, as device
is completely powered off. This can cause the GPIO keys to become
un-responsive after hibernate-exit.

To fix this problem, re-request IRQs in restore() callback, in the
hibernate exit flow.

Also, to keep the software in-sync with actual IRQ state in hardware,
disable and free the IRQs before entering hibernate(in freeze()
callback). Note that without this extra step, the IRQ re-request in
restore() may not work properly.

Besides this issue scenario, another usecase where this change
may be useful is - where these IRQs need to be handled by a low-power
co-processor during hibernate state. In this case too, these IRQs
need to be freed/re-requested during entry/exit transitions for
hibernate mode. so that co-processer can handle them, while main
processor is in hibernate.

Signed-off-by: Kamal Wadhwa <quic_kamalw@...cinc.com>
---
 drivers/input/keyboard/gpio_keys.c | 67 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 380fe8dab3b06379f9744e8190a4afcc0aee20b4..8c123e1b14ae34d3d15380eeb96b4a522732573c 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -1041,6 +1041,66 @@ gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 	}
 }
 
+static int gpio_keys_freeze(struct device *dev)
+{
+	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
+	struct gpio_button_data *bdata;
+	int i;
+
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
+		bdata = &ddata->data[i];
+
+		if (!bdata->irq)
+			continue;
+
+		mutex_lock(&ddata->disable_lock);
+		gpio_keys_disable_button(bdata);
+		mutex_unlock(&ddata->disable_lock);
+
+		devm_free_irq(dev, bdata->irq, bdata);
+	}
+
+	return 0;
+}
+
+static int gpio_keys_restore(struct device *dev)
+{
+	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
+	struct gpio_button_data *bdata;
+	int error = 0, i;
+	irq_handler_t isr;
+	unsigned long irqflags;
+	const char *desc;
+
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
+		bdata = &ddata->data[i];
+		desc = bdata->button->desc ? bdata->button->desc : "gpio_keys";
+		if (!bdata->irq)
+			continue;
+
+		if (bdata->gpiod) {
+			isr = gpio_keys_gpio_isr;
+			irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+		} else {
+			isr = gpio_keys_irq_isr;
+			irqflags = 0;
+		}
+
+		if (!bdata->button->can_disable)
+			irqflags = IRQF_SHARED;
+
+		error = devm_request_any_context_irq(dev, bdata->irq,
+						     isr, irqflags, desc, bdata);
+		if (error < 0) {
+			dev_err(dev, "Unable to claim irq %d; error %d\n",
+				bdata->irq, error);
+			return error;
+		}
+	}
+
+	return 0;
+}
+
 static int gpio_keys_suspend(struct device *dev)
 {
 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
@@ -1083,7 +1143,12 @@ static int gpio_keys_resume(struct device *dev)
 	return 0;
 }
 
-static DEFINE_SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
+static const struct dev_pm_ops gpio_keys_pm_ops = {
+	.freeze = gpio_keys_freeze,
+	.restore = gpio_keys_restore,
+	.suspend = gpio_keys_suspend,
+	.resume = gpio_keys_resume,
+};
 
 static void gpio_keys_shutdown(struct platform_device *pdev)
 {

---
base-commit: f2493655d2d3d5c6958ed996b043c821c23ae8d3
change-id: 20241018-unresponsive-gpio-keys-hibernate-31dfd03bf089

Best regards,
-- 
Kamal Wadhwa <quic_kamalw@...cinc.com>