[PATCH] input: gpio_keys: Don't report events on gpio failure

From: Bjorn Andersson
Date: Mon Jul 27 2015 - 21:50:21 EST


In the cases where the gpio chip fails to acquire the current state an
error is reported back to gpio_keys. This is currently interpreted as if
the line went high, which just confuses the developer.

This patch introduces an error print in this case and skipps the
reporting of a input event; to aid in debugging this issue.

Reported-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
---
drivers/input/keyboard/gpio_keys.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index ddf4045de084..3ce3298ac09e 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -336,8 +336,14 @@ static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
const struct gpio_keys_button *button = bdata->button;
struct input_dev *input = bdata->input;
unsigned int type = button->type ?: EV_KEY;
- int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
+ int state = gpio_get_value_cansleep(button->gpio);

+ if (state < 0) {
+ dev_err(input->dev.parent, "failed to get gpio state\n");
+ return;
+ }
+
+ state = (state ? 1 : 0) ^ button->active_low;
if (type == EV_ABS) {
if (state)
input_event(input, type, button->code, button->value);
--
1.8.2.2

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