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=-7.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 027B1C433E1 for ; Tue, 4 Aug 2020 19:28:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2D8F22BED for ; Tue, 4 Aug 2020 19:28:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="luRCZFvN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728004AbgHDT2R (ORCPT ); Tue, 4 Aug 2020 15:28:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726360AbgHDT2Q (ORCPT ); Tue, 4 Aug 2020 15:28:16 -0400 Received: from mail-qt1-x841.google.com (mail-qt1-x841.google.com [IPv6:2607:f8b0:4864:20::841]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A8DAC06174A for ; Tue, 4 Aug 2020 12:28:16 -0700 (PDT) Received: by mail-qt1-x841.google.com with SMTP id h21so25471419qtp.11 for ; Tue, 04 Aug 2020 12:28:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=QZPv3vyb9T7Ph9oNjo817uichWZWclCWnCIRIilrMbI=; b=luRCZFvNv1qw6XK0lP5bctiCtoKipS1zkSan+vF/4w0QNcp7tvBGPSXhl2Hu55Zni2 IVovI6W03P4sCwu3UjBAbkx9wSEIM5mQM1b/oB7V1Z/USbGH+S+9dq8ORM02WibWYy9b bgog7iYT5g2zlN7dzdekrUfbBalT2olGkwJrp7/9NhFWIV2ca2WOjnWPWf+Dn0IvLV1u /rmJodWFshUyd/AfAbXgpT+mnlWds6J8r8y3ipFHdaov9xAMXc+gV2A4Kn6NNbfyijtK RC6Atw7BnwPqoTwMP2okxisEmbqsqUZo0D27Afy3247WVNWN8l89zGmUWslqyy5QQDiD eWjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=QZPv3vyb9T7Ph9oNjo817uichWZWclCWnCIRIilrMbI=; b=g60y3c+U/AOW3+mAR5UP8Hkq0IJpZwq/Inww/VjG6oynPWyYJ8CZ9wZRkukbxR+WX2 JSm8ElWlQZd9z8a8AOg89SPUD+cFMiY4Tjo2lc1+fqCBPF5S/jvHtUSTNTbRgGKT98No K4qqCO03roVFrkwsA4WGVgGzysBqnNepaNBdqjae3tCnFp86qB6eHltg5/rucnBdxMKH 09TUZ0CsSxVUPo4q5DvaFoQUNdCI4P08agazjLrO6sFxUtJgeqns2lQqx+IDonvwwsir u50VHZJhpMNWYRlRvXyymNYUaTnJJbcPGGBuFgBNuvLUFb0GtyWiIrZ6X3/XuJ1Vl8h6 xuOg== X-Gm-Message-State: AOAM531pJM870H8/Du3+6svYDLIylNK2iCe0xQ9GaC+JCevAHWIENnjw pYwoIwmR9hkzlcF8MVFu9NxogmAY7KudJ+d9QjwFMg== X-Google-Smtp-Source: ABdhPJymsHefVLQVuV4G3IAFDTvR9UK59lInyk68B5dA9v9fdqqex2N6jbzDONS0DrBScUcDbjSWF5ZEeQa/M1q+dpA= X-Received: by 2002:aed:21da:: with SMTP id m26mr23617075qtc.197.1596569295695; Tue, 04 Aug 2020 12:28:15 -0700 (PDT) MIME-Version: 1.0 References: <20200725041955.9985-1-warthog618@gmail.com> <20200725041955.9985-8-warthog618@gmail.com> In-Reply-To: <20200725041955.9985-8-warthog618@gmail.com> From: Bartosz Golaszewski Date: Tue, 4 Aug 2020 21:28:04 +0200 Message-ID: Subject: Re: [PATCH v2 07/18] gpiolib: cdev: support edge detection for uAPI v2 To: Kent Gibson Cc: LKML , linux-gpio , Linus Walleij Content-Type: text/plain; charset="UTF-8" Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Sat, Jul 25, 2020 at 6:21 AM Kent Gibson wrote: > > Add support for edge detection to lines requested using > GPIO_GET_LINE_IOCTL. > > Signed-off-by: Kent Gibson > --- [snip!] > + > +static irqreturn_t edge_irq_thread(int irq, void *p) > +{ > + struct edge_detector *edet = p; > + struct line *line = edet->line; > + struct gpio_desc *desc = edge_detector_desc(edet); > + struct gpioline_event le; > + int ret; > + > + /* Do not leak kernel stack to userspace */ > + memset(&le, 0, sizeof(le)); > + > + /* > + * We may be running from a nested threaded interrupt in which case > + * we didn't get the timestamp from edge_irq_handler(). > + */ > + if (!edet->timestamp) { > + le.timestamp = ktime_get_ns(); IIRC Marc suggested using smp_rmw() here before reading the timestamp. Do we still need it or something changed? Bartosz