Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758996AbXFAXLX (ORCPT ); Fri, 1 Jun 2007 19:11:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754415AbXFAXLR (ORCPT ); Fri, 1 Jun 2007 19:11:17 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:57698 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754253AbXFAXLQ (ORCPT ); Fri, 1 Jun 2007 19:11:16 -0400 Subject: Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver From: Mauro Carvalho Chehab To: Thierry Merle Cc: video4linux-list@redhat.com, linux-kernel@vger.kernel.org, Andrew Morton , Jiri Slaby In-Reply-To: <465F3361.106@free.fr> References: <2172422218943432279@wsc.cz> <1180364420.21547.160.camel@localhost> <1180378677.21547.189.camel@localhost> <1180383071.21547.230.camel@localhost> <465B49EB.4080204@free.fr> <465BBAFB.30906@free.fr> <1180448712.21547.314.camel@localhost> <465C7920.2080203@free.fr> <1180467116.9509.73.camel@localhost> <465F3361.106@free.fr> Content-Type: text/plain Date: Fri, 01 Jun 2007 20:10:01 -0300 Message-Id: <1180739401.3904.50.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.10.0-5mdv2007.1 Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 28 > > This seems to be an interesting approach. > > > > > Interesting but impossible to do for ioctl calls. > When the application does a ioctl(fd_of_mnt_video0,VIDIOC_G_FMT,&arg) > for example, there is no way for the userspace helper to catch this ioctl. > The application could only open/read from the userspace helper's file > /mnt/video0. > ioctl would still have to be done on the kernel device driver. > I thought also about a /proc interface for decompression algorithms (a > helper would listen on a /proc file and write on another /proc file) but > /proc is not designed for that kind of thing. > A separate library seems to be the simplest solution. There are some ways for this to work. For example, you may create a helper device for the daemon driver to bind, even requiring it to have root permission. -- Cheers, Mauro - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/