From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowjanya Komatineni Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver Date: Mon, 6 Apr 2020 13:50:35 -0700 Message-ID: <23bfab09-b464-6e51-9843-06d13000e9b9@nvidia.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200bb96e-2d07-764f-9e14-55538dc742fd-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Content-Language: en-US Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dmitry Osipenko , thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, frankc-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, hverkuil-qWit8jRvyhVmR6Xm/wNWPw@public.gmane.org, sakari.ailus-X3B1VOXEql0@public.gmane.org, helen.koike-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org Cc: sboyd-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 4/6/20 1:45 PM, Dmitry Osipenko wrote: > External email: Use caution opening links or attachments > > > 04.04.2020 04:25, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> +static int chan_capture_kthread_start(void *data) >> +{ >> + struct tegra_vi_channel *chan =3D data; >> + struct tegra_channel_buffer *buf; >> + int err =3D 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 a= re >> + * 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->captur= e))) { >> + caps_inflight =3D chan->capture_reqs - chan->seque= nce; >> + /* >> + * 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 >=3D SYNCPT_FIFO_DEPTH) >> + break; > 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=20 continues 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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 BC031C2BA2B for ; Mon, 6 Apr 2020 20:50:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A439206C3 for ; Mon, 6 Apr 2020 20:50:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="eW0SjJUW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726331AbgDFUuo (ORCPT ); Mon, 6 Apr 2020 16:50:44 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:15856 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725957AbgDFUuo (ORCPT ); Mon, 6 Apr 2020 16:50:44 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 06 Apr 2020 13:50:25 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 06 Apr 2020 13:50:38 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 06 Apr 2020 13:50:38 -0700 Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 6 Apr 2020 20:50:37 +0000 Received: from [10.2.164.193] (10.124.1.5) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 6 Apr 2020 20:50:36 +0000 Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver To: Dmitry Osipenko , , , , , , CC: , , , , , 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> From: Sowjanya Komatineni Message-ID: <23bfab09-b464-6e51-9843-06d13000e9b9@nvidia.com> Date: Mon, 6 Apr 2020 13:50:35 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <200bb96e-2d07-764f-9e14-55538dc742fd@gmail.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To DRHQMAIL107.nvidia.com (10.27.9.16) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: quoted-printable Content-Language: en-US DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1586206225; bh=8bgqt/b8PFGRRWeo2lSm+TauOYvCItBjw9sgUHK/CCA=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding: Content-Language; b=eW0SjJUWjSpJ63g3bAqvYcAqqMzlz9T5IuBL2jGGZ+Rkgf+7rkdy4NT7EW4Wop3bU 1wN6eAohMi1UlBbpAypJo4WbG1IByczvedNpPY5WAJHiSLWCQ4BZVNgqelLVaWpwBL A02b4lsucmpMcC98w7bOg46Oz82Xn3Vbky2h2OcRjEKO59eGsouQpDt5ciwJkRWxpu Jzg0kv2WyRTDFUk54qdDd6ciXwfPZlXSR0vp32dEavzeBwds5gFUNH9cxfom3a1N3p r/j5nr9nkR9sng1W7SAWCbL7H+p7dHpwpuezI192cKsoZtylvS7RECx7+SpJMn7+cw gJJlWDGWxs8hA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/6/20 1:45 PM, Dmitry Osipenko wrote: > External email: Use caution opening links or attachments > > > 04.04.2020 04:25, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> +static int chan_capture_kthread_start(void *data) >> +{ >> + struct tegra_vi_channel *chan =3D data; >> + struct tegra_channel_buffer *buf; >> + int err =3D 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 a= re >> + * 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->captur= e))) { >> + caps_inflight =3D chan->capture_reqs - chan->seque= nce; >> + /* >> + * 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 >=3D SYNCPT_FIFO_DEPTH) >> + break; > 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=20 continues