If a button is a wake button, it may still be bouncing from the press
to wakeup the device by the time the gpio interrupts get enabled again
and / or the gpio_keys_report_state call from gpio_keys_resume may
find the button still pressed and report this as a new press.
This is undesirable, esp. since the powerbutton on tablets is typically
a wakeup source and uses the gpio_keys driver on some tablets, leading
to userspace immediately re-suspending the tablet after the powerbutton
is pressed, due to it seeing a powerbutton press.
This commit ignores wakeup button presses for the first 1 second after
resume (and while resumed, as the workqueue may run before the resume
function runs), avoiding this problem.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Note: maybe we should make WAKE_DEBOUNCE part of gpio_keys_button and
only do this when drivers / platform-data set this to a non-zero value ?
---
drivers/input/keyboard/gpio_keys.c | 50 ++++++++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 2 deletions(-)
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 2909365..ffede98 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -32,6 +32,8 @@
#include <linux/of_irq.h>
#include <linux/spinlock.h>
+#define WAKE_DEBOUNCE msecs_to_jiffies(1000)
+
struct gpio_button_data {
const struct gpio_keys_button *button;
struct input_dev *input;
@@ -42,10 +44,14 @@ struct gpio_button_data {
struct delayed_work work;
unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
+ unsigned long resume_time; /* in jiffies, for wakeup buttons */
+
unsigned int irq;
spinlock_t lock;
bool disabled;
bool key_pressed;
+ bool suspended;
+ bool resume_time_valid;
};
struct gpio_keys_drvdata {
@@ -353,6 +359,27 @@ static struct attribute_group gpio_keys_attr_group = {
.attrs = gpio_keys_attrs,
};
+static bool gpio_keys_ignore_wakeup_button_press(struct gpio_button_data *bdata)
+{
+ unsigned long flags;
+ bool ret = false;
+
+ if (!bdata->button->wakeup)
+ return ret;
+
+ spin_lock_irqsave(&bdata->lock, flags);
+
+ if (bdata->suspended)
+ ret = true; /* Our resume method did not run yet */
+ else if (bdata->resume_time_valid &&
+ time_before(jiffies, bdata->resume_time + WAKE_DEBOUNCE))
+ ret = true; /* Assume this is a wakeup press and ignore */
+
+ spin_unlock_irqrestore(&bdata->lock, flags);
+
+ return ret;
+}
+
static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
{
const struct gpio_keys_button *button = bdata->button;
@@ -366,6 +393,10 @@ static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
}
state = (state ? 1 : 0) ^ button->active_low;
+
+ if (state && gpio_keys_ignore_wakeup_button_press(bdata))
+ return;
+
if (type == EV_ABS) {
if (state)
input_event(input, type, button->code, button->value);
@@ -426,6 +457,9 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
BUG_ON(irq != bdata->irq);
+ if (gpio_keys_ignore_wakeup_button_press(bdata))
+ return IRQ_HANDLED;
+
spin_lock_irqsave(&bdata->lock, flags);
if (!bdata->key_pressed) {
@@ -819,13 +853,18 @@ static int gpio_keys_suspend(struct device *dev)
{
struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
struct input_dev *input = ddata->input;
+ unsigned long flags;
int i;
if (device_may_wakeup(dev)) {
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
- if (bdata->button->wakeup)
+ if (bdata->button->wakeup) {
+ spin_lock_irqsave(&bdata->lock, flags);
+ bdata->suspended = true;
+ spin_unlock_irqrestore(&bdata->lock, flags);
enable_irq_wake(bdata->irq);
+ }
}
} else {
mutex_lock(&input->mutex);
@@ -841,14 +880,21 @@ static int gpio_keys_resume(struct device *dev)
{
struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
struct input_dev *input = ddata->input;
+ unsigned long flags;
int error = 0;
int i;
if (device_may_wakeup(dev)) {
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
- if (bdata->button->wakeup)
+ if (bdata->button->wakeup) {
disable_irq_wake(bdata->irq);
+ spin_lock_irqsave(&bdata->lock, flags);
+ bdata->resume_time = jiffies;
+ bdata->resume_time_valid = true;
+ bdata->suspended = false;
+ spin_unlock_irqrestore(&bdata->lock, flags);
+ }
}
} else {
mutex_lock(&input->mutex);
--
2.9.3
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