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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 3596FC433E2 for ; Mon, 31 Aug 2020 00:10:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1506020720 for ; Mon, 31 Aug 2020 00:10:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="F3CnXuCn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726540AbgHaAKO (ORCPT ); Sun, 30 Aug 2020 20:10:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726404AbgHaAKN (ORCPT ); Sun, 30 Aug 2020 20:10:13 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4A06C061573; Sun, 30 Aug 2020 17:10:13 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id g207so3615087pfb.1; Sun, 30 Aug 2020 17:10:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=qLPEfrUi2jCIWCjZKRo6ZLLPjq6acaeWm3ALBWaznXk=; b=F3CnXuCn2pzKt3lquHeMzcnfquvPYqjIIQrtoVQ84O4mtYiNWRWGSKyMzzLuDuhGR4 Nssb7lzRM/8lmZn3YJ/SDCYbCK1WuoIDIOLyZIoCfI3iBh0ZaKcgxUz1KdFsHqvFBFhd JFgXycahfNDgPcdZzml0356S32S3kCnUReHH0TM+YcG0DuVLLILPwNtTxc6IzG//KJP5 vTDafW5Mg2L7N4q+XmztACw6cYDx5XNBq7kGiriHSjFiivFuSsbngdaP8f2YoCKeaF5z K24hzkPCpJZNT/X3sG6KbmlL/C7QVm79GnceeFKDJz4tJIzhc9ecsuX7QBcJclyJQnDI og+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=qLPEfrUi2jCIWCjZKRo6ZLLPjq6acaeWm3ALBWaznXk=; b=X/EWMkQVfuS4gERhDQqbdQYQXCRvkUWTXm+FvxNwZ+vQOj9apiJUlE/d7InOT2ro47 yXFlYoMstB83fsoAmPwL3tdyoRqz4ZtyI6Z2sNhShEjqWzE09y+kamXK5PF8EzS4svum EkbHnqEHcgDjXwHBX6mWcpnXhnbdSyxhZI8nP8NsQ/cyY+Ke1F/rYG/dhMeIerN+yHHP Xi26+tpM59Lnd4PKU/+5Lu1Io+XhlKc2v2D7WvLRHhaCw/MBc7uL8yCTY350SHDPBZQK VbZRHfY9hm/zwdPkH+Pl4ptl5AnIbtBiIZ8OiA9KhJDss9kvxk538V6uoDcltBXX1ap9 WIGA== X-Gm-Message-State: AOAM530SbBufLc4UdCfEc/QyTVcCsUAmHXKhNAwBM3YQdFM+bhaGMz6u FzI1a6j10wc/82QPXrGMbQw= X-Google-Smtp-Source: ABdhPJwWpKZRGsCUjZpmp33QErRgjRznzLg4iQdazkktoI5TvtWGJPMJCAhKW2BkvmSCD8WTPNRe2Q== X-Received: by 2002:a63:cb0a:: with SMTP id p10mr2440832pgg.314.1598832612609; Sun, 30 Aug 2020 17:10:12 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id q5sm5961917pfu.16.2020.08.30.17.10.11 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 30 Aug 2020 17:10:11 -0700 (PDT) Date: Sun, 30 Aug 2020 17:10:10 -0700 From: Guenter Roeck To: Laurent Pinchart Cc: Mauro Carvalho Chehab , Sakari Ailus , linux-uvc-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] media: uvcvideo: Fix race conditions Message-ID: <20200831001010.GA92208@roeck-us.net> References: <20200830150443.167286-1-linux@roeck-us.net> <20200830155833.GA6043@pendragon.ideasonboard.com> <20200830213621.GC6043@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200830213621.GC6043@pendragon.ideasonboard.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Mon, Aug 31, 2020 at 12:36:21AM +0300, Laurent Pinchart wrote: > Hi Guenter, > [ ... ] > I'll try to prototype what I envision would be a good solution in the > V4L2 core. If stars align, I may even try to push it one level up, to > the chardev layer. Would you then be able to test it ? > Sure, I'll be happy to do that. I ordered a couple of non-UVC webcams (pwc and gspca) from eBay for comparison. Both of those use the v4l2 locking mechanism, so we should be able to see the difference. Thanks, Guenter