From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753508AbdGCJML (ORCPT ); Mon, 3 Jul 2017 05:12:11 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:38905 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753391AbdGCJMK (ORCPT ); Mon, 3 Jul 2017 05:12:10 -0400 From: Bartosz Golaszewski To: Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH] gpiolib: skip unwanted events, don't convert them to opposite edge Date: Mon, 3 Jul 2017 11:12:03 +0200 Message-Id: <1499073123-13393-1-git-send-email-brgl@bgdev.pl> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The previous fix for filtering out of unwatched events was not entirely correct. Instead of skipping the events we don't want, they are now interpreted as events with opposing edge. In order to fix it: always read the GPIO line value on interrupt and only emit the event if it corresponds with the event type we requested. Fixes: ad537b822577 ("gpiolib: fix filtering out unwanted events") Signed-off-by: Bartosz Golaszewski --- Hi Linus, I tested my previous fix on a real board, where I got a storm of interrupts from simply playing with a GPIO manually. It looked ok so I posted the patch, but I didn't notice that when waiting for rising-edge events, all falling-edge events got interpreted as such. This patch should actually fix this bug. Tested carefully with gpio-mockup this time. drivers/gpio/gpiolib.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a42a1ee..2e96b3d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -704,24 +704,23 @@ static irqreturn_t lineevent_irq_thread(int irq, void *p) { struct lineevent_state *le = p; struct gpioevent_data ge; - int ret; + int ret, level; ge.timestamp = ktime_get_real_ns(); + level = gpiod_get_value_cansleep(le->desc); if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { - int level = gpiod_get_value_cansleep(le->desc); - if (level) /* Emit low-to-high event */ ge.id = GPIOEVENT_EVENT_RISING_EDGE; else /* Emit high-to-low event */ ge.id = GPIOEVENT_EVENT_FALLING_EDGE; - } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { + } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) { /* Emit low-to-high event */ ge.id = GPIOEVENT_EVENT_RISING_EDGE; - } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { + } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) { /* Emit high-to-low event */ ge.id = GPIOEVENT_EVENT_FALLING_EDGE; } else { -- 2.9.3