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 A8AF2C2BA2B for ; Mon, 6 Apr 2020 20:45:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86AF6206C3 for ; Mon, 6 Apr 2020 20:45:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rAkxhqam" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726112AbgDFUpb (ORCPT ); Mon, 6 Apr 2020 16:45:31 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:44912 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgDFUpa (ORCPT ); Mon, 6 Apr 2020 16:45:30 -0400 Received: by mail-lj1-f193.google.com with SMTP id p14so1196134lji.11; Mon, 06 Apr 2020 13:45:27 -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=2TwAK6CIvOGj1m1Wxupnzx1SAQcBc4vTS5R9uhjDJic=; b=rAkxhqam2uIBwwk5bUMs5DFLIVzXPiDcnVEO8xu4lgjCDxE7N9DAv35EPx6CDA1lEX TCwv+wafC53L9JJciyGTHBfWMXTWc9yLe/7/qUVWePJuYzt0MRs99twMThOCEaH/r5ps vPD1l7ehtt7iKAgRGGi7wNqSrzUHFT3lANJzGgRa8IbTgpwmSWJObdPYeTVBKwGCwqeX K565HKd/wu9dznMlu1Ib1zQ4rENCztxnQmmDQis2Ngz+IF126hGjQE47WqzSvrlvf1ta fQGPgRE4exP9M7YOp+D6Z8F2MtRZq7L2+kd4I1hDSI5IfBxWHjli8kgO/KxShMbQ0yZ4 iPuA== 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=2TwAK6CIvOGj1m1Wxupnzx1SAQcBc4vTS5R9uhjDJic=; b=QcwVWcVQ693D0tqFkl5xvz6iZuIDizBPE7zkZzOyTu8n6HHRa+lMJ/AoCr+K2dtLMH 4GJ3BKxRINs1x96pQWTzIT0Uep2IsX4X361UHF0a+ywNtue27tMIyUVS8Z28+ZYKKF5g KqouKACqOyUXpm3sI6yC2DoPUZ7mBdAEL3oZ5irfalK7GK1MyF+X0FKAzmsqytOR5dax UpBUYrlCTRyEGbWdGZ8IyCjKPzIbOYpnQvA2QHpllVDprsdtdL85+7vsl+E/kjlXmwbk NKBlDvlD6BDuxLzbFmIlGJPF7uXf3Qw191AGCINRlJQx2f5lNfNixonnrPg4vVzStT1i Bguw== X-Gm-Message-State: AGi0Pubrqb6UcI0RK18Tunmd68NvfAqbxhVJH/hJ7r8WODM58hWgekhK 8FFcd5dNOwZL0RIm6Rkor8ZgKrz6 X-Google-Smtp-Source: APiQypLClTno4SZElehZQYVE+lDHbwt+yIw7aDUqIsFsXrMH5fE9MXJV+hbnagr8GItROxrsruhlOA== X-Received: by 2002:a2e:45c2:: with SMTP id s185mr633822lja.66.1586205926367; Mon, 06 Apr 2020 13:45:26 -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 m13sm1568316lfk.12.2020.04.06.13.45.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 06 Apr 2020 13:45:25 -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> From: Dmitry Osipenko Message-ID: <200bb96e-2d07-764f-9e14-55538dc742fd@gmail.com> Date: Mon, 6 Apr 2020 23:45:24 +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: <1585963507-12610-7-git-send-email-skomatineni@nvidia.com> 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 04.04.2020 04:25, Sowjanya Komatineni пишет: > +static int chan_capture_kthread_start(void *data) > +{ > + struct tegra_vi_channel *chan = data; > + struct tegra_channel_buffer *buf; > + int err = 0; > + int caps_inflight; > + > + set_freezable(); > + > + while (1) { > + try_to_freeze(); > + > + wait_event_interruptible(chan->start_wait, > + !list_empty(&chan->capture) || > + kthread_should_stop()); > + /* > + * Frame start and MW_ACK_DONE syncpoint condition FIFOs are > + * of max depth 2. So make sure max 2 capture requests are > + * in process by the hardware at a time. > + */ > + while (!(kthread_should_stop() || list_empty(&chan->capture))) { > + caps_inflight = chan->capture_reqs - chan->sequence; > + /* > + * Source is not streaming if error is non-zero. > + * So, do not dequeue buffers on capture error or when > + * syncpoint requests in FIFO are full. > + */ > + if (err || caps_inflight >= SYNCPT_FIFO_DEPTH) > + break; Am I understanding correctly that this thread will take 100% CPU, spinning here, if more than 2 frame-captures queued?