From patchwork Mon Dec 28 12:47:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 353144 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4387C43381 for ; Mon, 28 Dec 2020 16:07:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEC192074A for ; Mon, 28 Dec 2020 16:07:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392960AbgL1QGz (ORCPT ); Mon, 28 Dec 2020 11:06:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:55060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389506AbgL1N0g (ORCPT ); Mon, 28 Dec 2020 08:26:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7BAF22072C; Mon, 28 Dec 2020 13:26:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609161980; bh=JMp0wial69jrL6aFyW+zOQgg+WkIMrPu8HjSfNA2Cf4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bE7pYMZmUXaJN2XFTVmtBYSSCppBYM9WeBhBnz+/l317U3BtS2wnhj4ZSCbv/A+ak lZJJaMJ5lBH/hyI5JhQUxf1izG0RO1Bp6g6aXJ5YfHTLubrk3QXC7U+p8inyxE7wj3 KVPZVC7NrroMELpnhZ0RrYBn0SYPsIdtjWDq+a/I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Jander , Oleksij Rempel , Dmitry Torokhov , Sasha Levin Subject: [PATCH 4.19 147/346] Input: ads7846 - fix race that causes missing releases Date: Mon, 28 Dec 2020 13:47:46 +0100 Message-Id: <20201228124926.896197443@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Jander [ Upstream commit e52cd628a03f72a547dbf90ccb703ee64800504a ] If touchscreen is released while busy reading HWMON device, the release can be missed. The IRQ thread is not started because no touch is active and BTN_TOUCH release event is never sent. Fixes: f5a28a7d4858f94a ("Input: ads7846 - avoid pen up/down when reading hwmon") Co-developed-by: Oleksij Rempel Signed-off-by: David Jander Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20201027105416.18773-1-o.rempel@pengutronix.de Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin --- drivers/input/touchscreen/ads7846.c | 44 +++++++++++++++++------------ 1 file changed, 26 insertions(+), 18 deletions(-) diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index a2f45aefce08a..0fbad337e45a3 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -199,6 +199,26 @@ struct ads7846 { #define REF_ON (READ_12BIT_DFR(x, 1, 1)) #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) +static int get_pendown_state(struct ads7846 *ts) +{ + if (ts->get_pendown_state) + return ts->get_pendown_state(); + + return !gpio_get_value(ts->gpio_pendown); +} + +static void ads7846_report_pen_up(struct ads7846 *ts) +{ + struct input_dev *input = ts->input; + + input_report_key(input, BTN_TOUCH, 0); + input_report_abs(input, ABS_PRESSURE, 0); + input_sync(input); + + ts->pendown = false; + dev_vdbg(&ts->spi->dev, "UP\n"); +} + /* Must be called with ts->lock held */ static void ads7846_stop(struct ads7846 *ts) { @@ -215,6 +235,10 @@ static void ads7846_stop(struct ads7846 *ts) static void ads7846_restart(struct ads7846 *ts) { if (!ts->disabled && !ts->suspended) { + /* Check if pen was released since last stop */ + if (ts->pendown && !get_pendown_state(ts)) + ads7846_report_pen_up(ts); + /* Tell IRQ thread that it may poll the device. */ ts->stopped = false; mb(); @@ -605,14 +629,6 @@ static const struct attribute_group ads784x_attr_group = { /*--------------------------------------------------------------------------*/ -static int get_pendown_state(struct ads7846 *ts) -{ - if (ts->get_pendown_state) - return ts->get_pendown_state(); - - return !gpio_get_value(ts->gpio_pendown); -} - static void null_wait_for_sync(void) { } @@ -871,16 +887,8 @@ static irqreturn_t ads7846_irq(int irq, void *handle) msecs_to_jiffies(TS_POLL_PERIOD)); } - if (ts->pendown && !ts->stopped) { - struct input_dev *input = ts->input; - - input_report_key(input, BTN_TOUCH, 0); - input_report_abs(input, ABS_PRESSURE, 0); - input_sync(input); - - ts->pendown = false; - dev_vdbg(&ts->spi->dev, "UP\n"); - } + if (ts->pendown && !ts->stopped) + ads7846_report_pen_up(ts); return IRQ_HANDLED; }