Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp2061112ybz; Thu, 30 Apr 2020 10:09:52 -0700 (PDT) X-Google-Smtp-Source: APiQypJVXQWvYLitkbRCBVOMd5bJKiVyE/vKKVyFLJkdQ+g+b3U86FZl807AGQ/BgWzTm2guyyrq X-Received: by 2002:a17:906:6441:: with SMTP id l1mr3831749ejn.148.1588266592485; Thu, 30 Apr 2020 10:09:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1588266592; cv=none; d=google.com; s=arc-20160816; b=MsgelIpft/rDz/I+jjKCKyVCHY1ZzX/9oGcAP1C+DYxQM90z0A8Glz+Ez4RXoVhLnC GrFayGLN7y8Lx2Dv8k5Nyd8dKgDvVMev9DithuFgqPSA8pMndQMGKt1KWOysoVQX9EAB 9EThZXL1wg/e3irDH03Ufcy4mQgetX5KDW5RQRdnc/h9eG1QSBAqmS89Qy1XBiujHYdl +plGJ7pH152ymSveNtqQ3rFC7pufssyJUbYP+5Gt7GqkMgzgYCr3zUB7tNbjf/8VO7iQ HFqKUBFdVzcJU/ZTkxXOkkQjfBArBllc8kJ8TDr9WSJRXoXokqIkfQjIiQcd5na5ZLW4 RbPQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:dkim-signature:content-language :content-transfer-encoding:in-reply-to:mime-version:user-agent:date :message-id:references:cc:to:from:subject; bh=gKejJOxcNXFjey06HQS8SHBbL2xiLFZnrxw6ec+17Pc=; b=JLXndBIHxEsCmCIfsISEqsWz89lYuW53K1CCd7hDUbqlpV5hHuHpi6UcumAPBCjuv5 lIq8dl0poCAs3CmnzD2uQ2kPkfoLap2D5cVIoMNX8Y7W7H/19h5UHb7vXujLvfJOVKuF z2sUw2f6hOE0sLbR0adH/UFsR20JuQByxuaFvYBI6GoCcdezL8CyrD4EekvK4hcIC4/q ErHqziYPCAwUDrWH7GAlrlM5pP4ZxHcGkozVPWl70s5a0Ej9Q3p5Rn4exJWse8auciUp LYAEVLzVxKwAfzPx3CgSqGOVabKZ0YAtIHu6apRAJT1poVoDYi4ci+wby1ujAsWW+Ukq MHyA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=g1cvV1Ej; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id t4si133312ejr.418.2020.04.30.10.09.29; Thu, 30 Apr 2020 10:09:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=g1cvV1Ej; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726565AbgD3RH6 (ORCPT + 99 others); Thu, 30 Apr 2020 13:07:58 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:15988 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726272AbgD3RH6 (ORCPT ); Thu, 30 Apr 2020 13:07:58 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 30 Apr 2020 10:07:45 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 30 Apr 2020 10:07:57 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 30 Apr 2020 10:07:57 -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; Thu, 30 Apr 2020 17:07:57 +0000 Received: from [10.2.165.152] (10.124.1.5) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 30 Apr 2020 17:07:56 +0000 Subject: Re: [RFC PATCH v11 6/9] media: tegra: Add Tegra210 Video input driver From: Sowjanya Komatineni To: Dmitry Osipenko , , , , , , CC: , , , , , References: <1588197606-32124-1-git-send-email-skomatineni@nvidia.com> <1588197606-32124-7-git-send-email-skomatineni@nvidia.com> <4da289e6-036f-853b-beb4-379d6462adb0@gmail.com>

<7d31d24f-f353-7e82-3ff9-cdba8b773d1e@nvidia.com> Message-ID: <06a4a067-8d54-4322-b2a6-14e82eaeda29@nvidia.com> Date: Thu, 30 Apr 2020 10:06:30 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <7d31d24f-f353-7e82-3ff9-cdba8b773d1e@nvidia.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) 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=1588266465; bh=gKejJOxcNXFjey06HQS8SHBbL2xiLFZnrxw6ec+17Pc=; h=X-PGP-Universal:Subject:From:To:CC:References:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding: Content-Language; b=g1cvV1EjFUY0/YRB8FTfjLGhfHHm+OlcpVnJmROFod9EqiERZm3dQGunHXNaaa8fl DF/Dq0Ws62+JbiuUxrlVlJ+20dymwmelZotvcepsenDbGDlHIgUCe54bfLTbMJ+7/l IlaPaXafAxEeyizXWpejtN4Pgi79avT6JCrLhoB5qSlKyBg0/RAhGihRt8mAD4uUl2 uCGe1WOGfa1iHl++TlL24Db/0YvWPtZ0muYKlKPiXBexNGMgvaCL3ZaMv6XQJZwz/H 7+8GgNF0zRsbMP3iroz+M5ifwNSYV/QV3aBDJt4IaKXfR69KLabjVSiHVTVZEslEEW 3mwCFW+ABCAAg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/30/20 9:29 AM, Sowjanya Komatineni wrote: > > On 4/30/20 9:04 AM, Sowjanya Komatineni wrote: >> >> On 4/30/20 7:13 AM, Dmitry Osipenko wrote: >>> 30.04.2020 17:02, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>> 30.04.2020 16:56, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>> 30.04.2020 01:00, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>>> +static int chan_capture_kthread_finish(void *data) >>>>>> +{ >>>>>> +=C2=A0=C2=A0=C2=A0 struct tegra_vi_channel *chan =3D data; >>>>>> +=C2=A0=C2=A0=C2=A0 struct tegra_channel_buffer *buf; >>>>>> + >>>>>> +=C2=A0=C2=A0=C2=A0 set_freezable(); >>>>>> + >>>>>> +=C2=A0=C2=A0=C2=A0 while (1) { >>>>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 try_to_freeze(); >>>>> I guess it won't be great to freeze in the middle of a capture=20 >>>>> process, so: >>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (list_empty(&chan->done= )) >>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 tr= y_to_freeze(); >>>> And here should be some locking protection in order not race with the >>>> chan_capture_kthread_start because kthread_finish could freeze before >>>> kthread_start. >>> Or maybe both start / finish threads should simply be allowed to freeze >>> only when both capture and done lists are empty. >>> >>> if (list_empty(&chan->capture) && >>> =C2=A0=C2=A0=C2=A0=C2=A0 list_empty(&chan->done)) >>> =C2=A0=C2=A0=C2=A0=C2=A0try_to_freeze(); >> >> good to freeze when not in middle of the frame capture but why should=20 >> we not allow freeze in between captures? >> >> Other drivers do allow freeze in between frame captures. >> >> I guess we can freeze before dequeue for capture and in finish thread=20 >> we can freeze after capture done. This also don't need to check for=20 >> list_empty with freeze to allow between frame captures. >> > Also if we add check for both lists empty, freeze is not allowed as=20 > long as streaming is going on and in case of continuous streaming=20 > freeze will never happen. Hi Dmitry, Will update in v12 to not allow freeze in middle of a frame capture. Can you please confirm on above if you agree to allow freeze to happen=20 in b/w frame captures? Also as most feedback has been received from you by now, appreciate if=20 you can provide all in this v11 if you have anything else so we will not=20 have any new changes after v12. Thanks Sowjanya