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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 2AF09C2BA1A for ; Mon, 6 Apr 2020 21:11:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF922206B8 for ; Mon, 6 Apr 2020 21:11:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hL1ZoGrZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726112AbgDFVLT (ORCPT ); Mon, 6 Apr 2020 17:11:19 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:38205 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgDFVLS (ORCPT ); Mon, 6 Apr 2020 17:11:18 -0400 Received: by mail-lj1-f196.google.com with SMTP id v16so1321178ljg.5; Mon, 06 Apr 2020 14:11:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=BLFfj2ck0MQtzj26NMFplS6l4cmd6DLaFaHtSAPxxaI=; b=hL1ZoGrZsgb0I8HNso0c0WiLYTwVsFKm6wqzdXT8kzWpLZL47a9qF2UI00ftizEgy2 VDYFlZssv5FoINjrvS+y8swT8CCmSeYOwwooXeLd3rXr2Nzvgi1o2F4/XtVjpgOAvO5w MalwQMOvgIS72ApEYe6ODUsBv/GPmCooftFkz7DtQYkmoUJRvKLAxbl85HkU7o4mXL6T gaa6Yaw/BLngInnjszekYPOeH7B/4RaZmYP0JB+4ag3gAgt8aMfjcJ49rvMeSuLm03Ge h6/PMbbxgNxaIEGjtDyJ65vy8srxUEH1joq4drbTWDH0WI5/ntNPjcHzYASc9LIHcKDQ 3sSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=BLFfj2ck0MQtzj26NMFplS6l4cmd6DLaFaHtSAPxxaI=; b=qgFLE2Zmxo3jn0dpkqAWDww7Mu2DFHFyNSpZoePhYXlHE6Ey7yjMWDzvL6J9CNiUM4 8BA4d/ZPeC17NHq8Awqy2iQm1BPT91rhs2HntezqQ8Lo7ww8+4CRb+C0FJmLAWbCYjII LNSW2bl9OhneEgHJOkPITKiu6Zi86ck0T17o/BwFg2GNYOFRPOYz6oX3rgz3dt+w/YW0 PqNu1fkPKxgvkrGSWUcF16se5JbpVoXwohrYRibKe/fNH2evL6+fT9w3uI3DEDlKMlVu JeP1E4TKtmNdgYF96QeEsTdXb2NG2hVbJo5u+4GIjs/MvcWxOHoBj0M0RRCqv+kTIuqN el6w== X-Gm-Message-State: AGi0Pua45sgOUIM5Or5IgPnisXCuuZoPEK0boo/IA2qIApWFORE3BCuI 3KsrpQXPh3Nyx+5LelJFj2EFCEYA X-Google-Smtp-Source: APiQypILGKh47GhOUeTOUq39iuuxxtQkTWa2ixzbKDJgnTXPVV82LRf26aFJWl5KHUeLt2/IK7Yd9w== X-Received: by 2002:a2e:8e3a:: with SMTP id r26mr731670ljk.233.1586207475793; Mon, 06 Apr 2020 14:11:15 -0700 (PDT) Received: from [192.168.2.145] (ppp91-78-208-152.pppoe.mtu-net.ru. [91.78.208.152]) by smtp.googlemail.com with ESMTPSA id y16sm10306806ljc.78.2020.04.06.14.11.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 06 Apr 2020 14:11:15 -0700 (PDT) Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, frankc@nvidia.com, hverkuil@xs4all.nl, sakari.ailus@iki.fi, helen.koike@collabora.com Cc: sboyd@kernel.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <1585963507-12610-1-git-send-email-skomatineni@nvidia.com> <1585963507-12610-7-git-send-email-skomatineni@nvidia.com> <200bb96e-2d07-764f-9e14-55538dc742fd@gmail.com> <23bfab09-b464-6e51-9843-06d13000e9b9@nvidia.com> <08cd31d5-e8b9-4d3a-fb0e-0e4462947d96@nvidia.com> <12a834ac-52b1-6dc0-7d3a-3e6a1fa85a2a@gmail.com> From: Dmitry Osipenko Message-ID: Date: Tue, 7 Apr 2020 00:11:13 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 07.04.2020 00:02, Sowjanya Komatineni пишет: >>>>>> Am I understanding correctly that this thread will take 100% CPU, >>>>>> spinning here, if more than 2 frame-captures queued? >>>>> on more than 2 frames captures, it breaks thread and on next wakeup it >>>>> continues >>>> The wait_event() won't wait if condition is true. >>> condition is checked when waitqueue is woken up >> https://elixir.bootlin.com/linux/v5.6.2/source/include/linux/wait.h#L462 > > process is put to sleep until the condition evaluates to true or signal > is received. > > condition is checked each time the waitqueue head is woken up. This is a wrong assumption in accordance to the code.