linux-kernel - [PATCH] Input: gpio_keys_polled - always use gpiod_get_value

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 19 Oct 2016 16:41:07 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     linux-input@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, Hans de Goede <hdegoede@...hat.com>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Aaron Lu <aaron.lu@...el.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH] Input: gpio_keys_polled - always use gpiod_get_value_cansleep

It does not matter if given GPIO may sleep or not when reading state,
polling is always done in a non-atomic context, so we should always
be able to simply use gpiod_get_value_cansleep().

Also let's note in the logs when we fail to read gpio state.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/input/keyboard/gpio_keys_polled.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index daef8ea..3c79158 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -34,7 +34,6 @@ struct gpio_keys_button_data {
 	int last_state;
 	int count;
 	int threshold;
-	int can_sleep;
 };
 
 struct gpio_keys_polled_dev {
@@ -76,16 +75,17 @@ static void gpio_keys_polled_check_state(struct input_polled_dev *dev,
 {
 	int state;
 
-	if (bdata->can_sleep)
-		state = !!gpiod_get_value_cansleep(bdata->gpiod);
-	else
-		state = !!gpiod_get_value(bdata->gpiod);
-
-	gpio_keys_button_event(dev, button, state);
+	state = gpiod_get_value_cansleep(bdata->gpiod);
+	if (unlikely(state < 0)) {
+		dev_err(input->dev.parent,
+			"failed to get gpio state: %d\n", state);
+	} else {
+		gpio_keys_button_event(dev, button, state);
 
-	if (state != bdata->last_state) {
-		bdata->count = 0;
-		bdata->last_state = state;
+		if (state != bdata->last_state) {
+			bdata->count = 0;
+			bdata->last_state = state;
+		}
 	}
 }
 
@@ -341,7 +341,6 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
 			}
 		}
 
-		bdata->can_sleep = gpiod_cansleep(bdata->gpiod);
 		bdata->last_state = -1;
 		bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
 						pdata->poll_interval);
-- 
2.8.0.rc3.226.g39d4020


-- 
Dmitry