From patchwork Mon Oct 5 05:24:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 268013 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 B7FF2C4363A for ; Mon, 5 Oct 2020 05:24:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82E4920795 for ; Mon, 5 Oct 2020 05:24:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bVhw6HJa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725857AbgJEFYX (ORCPT ); Mon, 5 Oct 2020 01:24:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725267AbgJEFYX (ORCPT ); Mon, 5 Oct 2020 01:24:23 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C32CC0613CE; Sun, 4 Oct 2020 22:24:23 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id kk9so4824388pjb.2; Sun, 04 Oct 2020 22:24:23 -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:mime-version:content-disposition; bh=BNYjHkQnOMekLYDlnrC4+qnb1F1o0CegnvK1HRf+M3E=; b=bVhw6HJaIcRnGYg13Gwvf/nRUPEDAzphy5SgMUlQn0owx2LFY/gCCAH8tInL5h6Bm8 9tPOvz/tin7psVeAEAqG1LZlZ7qaWKqRQsG0e5ySKJIyhJ8nwPcRy4VwtN9PAeVI1Owm BPlCOjl8TqDwEFd6fzfq6aVntVri/YLG4Q43yWXYImE/pWNUNVpLhls2O2qjscsa3Rs+ hLa6BhVhheFTuL26yibuUqP6dCR3mWEPq5bc3nRwltRI2aIPHWhSXC97782P/ZKigFsg yCuyi/qW9cH/0FrZK5ySm5BUtnrobkrGpNlkD8RUpBytQnvYHFfPPDN3mgQsj0D1HO31 BAqw== 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:mime-version :content-disposition; bh=BNYjHkQnOMekLYDlnrC4+qnb1F1o0CegnvK1HRf+M3E=; b=Uj/2BRDdOsg2xsWDLup+CdO+AsKc1001LhYeCTImB/C/InNtBS19pzoCP4YbqjGnn+ XnG5x3IomDf4KU+xXFUS/g8cNuaYuS8MBn8dOQZMw0LprQRTxtBL/2Zqvc8AObfyOQpd Le2ukZ6MrstxriVI+/GBUQZXzcm7yW/LGCdhSyoHnoKjoF61+kfpFXO8RyPPZ78JZVu/ W33josjzQUXvuXhj6kPFx/Kpg3m8G349wJAUFBpNOxURTopVvmGrzVKMTVEXj7rNUp+X gl1oOs35mEfkr2WvrW/NeCMgwlxcOGxbYmrq7xY+DsCqSftByElFkbhaiIdY11WCIL20 DVOQ== X-Gm-Message-State: AOAM531Clxaff/073D8C7KIeCnp050DQoUwe0Oy6pMYzQ5eX0+OcfKi9 C6PTS9XNZNK3+/74xmRDbzY= X-Google-Smtp-Source: ABdhPJya5lgMUpviFhKpyV4jVKOyVJKf+Zu6q1nCYOlSz1S7dX9sswceSqRH3HhXDhrwTa6/Os/LKg== X-Received: by 2002:a17:90b:797:: with SMTP id l23mr14809114pjz.176.1601875463037; Sun, 04 Oct 2020 22:24:23 -0700 (PDT) Received: from dtor-ws ([2620:15c:202:201:a6ae:11ff:fe11:fcc3]) by smtp.gmail.com with ESMTPSA id t12sm9228351pgk.32.2020.10.04.22.24.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 Oct 2020 22:24:22 -0700 (PDT) Date: Sun, 4 Oct 2020 22:24:20 -0700 From: dmitry.torokhov@gmail.com To: Jonathan Cameron Cc: Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Kukjin Kim , Krzysztof Kozlowski , =?utf-8?b?TWljaGHFgiBNaXJvc8WCYXc=?= , Andrzej Pietrasiewicz , linux-iio@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] iio: adc: exynos: do not rely on 'users' counter in ISR Message-ID: <20201005052420.GA3262631@dtor-ws> MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org The order in which 'users' counter is decremented vs calling drivers' close() method is implementation specific, and we should not rely on it. Let's introduce driver private flag and use it to signal ISR to exit when device is being closed. This has a side-effect of fixing issue of accessing inut->users outside of input->mutex protection. Reported-by: Andrzej Pietrasiewicz Signed-off-by: Dmitry Torokhov Acked-by: Krzysztof Kozlowski --- drivers/iio/adc/exynos_adc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 22131a677445..7eb2a5df6e98 100644 --- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -135,6 +135,8 @@ struct exynos_adc { u32 value; unsigned int version; + bool ts_enabled; + bool read_ts; u32 ts_x; u32 ts_y; @@ -633,7 +635,7 @@ static irqreturn_t exynos_ts_isr(int irq, void *dev_id) bool pressed; int ret; - while (info->input->users) { + while (info->ts_enabled) { ret = exynos_read_s3c64xx_ts(dev, &x, &y); if (ret == -ETIMEDOUT) break; @@ -712,6 +714,8 @@ static int exynos_adc_ts_open(struct input_dev *dev) { struct exynos_adc *info = input_get_drvdata(dev); + info->ts_enabled = true; + mb(); enable_irq(info->tsirq); return 0; @@ -721,6 +725,8 @@ static void exynos_adc_ts_close(struct input_dev *dev) { struct exynos_adc *info = input_get_drvdata(dev); + info->ts_enabled = false; + mb(); disable_irq(info->tsirq); }