From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 91047C55179 for ; Tue, 27 Oct 2020 03:48:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55A302168B for ; Tue, 27 Oct 2020 03:48:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aprXITN1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2505232AbgJ0Dsz (ORCPT ); Mon, 26 Oct 2020 23:48:55 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:36674 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406292AbgJ0Dsz (ORCPT ); Mon, 26 Oct 2020 23:48:55 -0400 Received: by mail-pg1-f194.google.com with SMTP id z24so1209pgk.3; Mon, 26 Oct 2020 20:48:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=pIU+eJrKipvoL+xJlvndpIp8jUWD+TSQyGYQmcJjhw4=; b=aprXITN1sTOLCaHYTqf/JETAhA58UEL8qvD5zDv7FFIC6wCfh8WQNvh0TZm0d/HBE7 mHxgcuRVWu4+8JXfdRdA1HVFh2Pd2dYScOZQwqPCyhfn+CjVzEA51X+rX/6qnS+R6mSz dmux6wUIaYTzhkyR6D3c+qRENe8kd9szbqFq8lDxLZWLcKpig3gxxsW0byQxeB1AKoA/ MVo5vodz0Sz/0a3YT5xnYcvppeUFQU6CwkhQ/GXU6bs9MKuI/H46BeDk4WUz+BgV0omW Ra/4lZsvgLj8tj1S36kAVHK4cSwQe7zFIHAPpJ1emqttzZNeojxFa35dYJJ1GiWKh5O0 114w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=pIU+eJrKipvoL+xJlvndpIp8jUWD+TSQyGYQmcJjhw4=; b=iydY5O8kvZGHmKd0V5LFhUBeLOV3nqgxM1FD/Jrln8G2BLT6i0SYaGx7ReIGETtjlo dbCwRXw+HHqILzzqQjzOM3RuzNYBK43V3/kJkjKB022UGlbEWIGBSBGm5c1eY388tgwB JJ67MIniVpbCISvMg0SHh8Gy69uJJsmCk1lZCtsMm2pvxeUiZnMdcUoizfGpVFLKCFyu mGxtWtzjgDju1HWcy4AkCrG+p5Ix1Jk+hqmMF28f+7ZFEiM3HGYaTRPyTKCI6XuHk1l4 OanVMiDd3pX4YqREdGkFlopjLgLCRhY4/g+VTFihadx1DiAQqxnSXsRu3dPJo25lFhdu bcQw== X-Gm-Message-State: AOAM530llYzLBS2oGn5UTdMP9knPE10XVpRxX0IEHd+f/z1I6oYcbLoK 4WNWymFnoZEtpHimJuu2J3w= X-Google-Smtp-Source: ABdhPJxCHzOMI7tZGakI6vZ2AyCAuJbwavSXmfnqi0fIf022nRW9pcRIhJYmKEQ2vNVI0PsOt/fXAg== X-Received: by 2002:a63:7c8:: with SMTP id 191mr185690pgh.410.1603770534330; Mon, 26 Oct 2020 20:48:54 -0700 (PDT) Received: from dtor-ws ([2620:15c:202:201:a6ae:11ff:fe11:fcc3]) by smtp.gmail.com with ESMTPSA id lk13sm201234pjb.43.2020.10.26.20.48.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 20:48:53 -0700 (PDT) Date: Mon, 26 Oct 2020 20:48:51 -0700 From: Dmitry Torokhov To: Oleksij Rempel Cc: Alexandru Ardelean , David Jander , kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org Subject: Re: [PATCH v1] Input: touchscreen: ads7846.c: Fix race that causes missing releases Message-ID: <20201027034851.GH444962@dtor-ws> References: <20201026132117.20887-1-o.rempel@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201026132117.20887-1-o.rempel@pengutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oleksij, On Mon, Oct 26, 2020 at 02:21:17PM +0100, Oleksij Rempel wrote: > From: David Jander > > 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: David Jander > Signed-off-by: David Jander > Signed-off-by: Oleksij Rempel > --- > drivers/input/touchscreen/ads7846.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c > index ea31956f3a90..0236a119c52d 100644 > --- a/drivers/input/touchscreen/ads7846.c > +++ b/drivers/input/touchscreen/ads7846.c > @@ -211,10 +211,26 @@ static void ads7846_stop(struct ads7846 *ts) > } > } > > +static int get_pendown_state(struct ads7846 *ts); Not a fan forward declarations, just move the definition if needed. > + > /* Must be called with ts->lock held */ > static void ads7846_restart(struct ads7846 *ts) > { > + unsigned int pdstate; I do not see it being used. Do you have more patches for the driver? > + > if (!ts->disabled && !ts->suspended) { > + /* Check if pen was released since last stop */ > + if (ts->pendown && !get_pendown_state(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"); I wonder if we should not have ads7846_report_pen_up(struct ads7846 *ts) > + } > + > /* Tell IRQ thread that it may poll the device. */ > ts->stopped = false; > mb(); > -- > 2.28.0 > Thanks. -- Dmitry