Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753355Ab0LaLr7 (ORCPT ); Fri, 31 Dec 2010 06:47:59 -0500 Received: from casper.infradead.org ([85.118.1.10]:55032 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179Ab0LaLr6 (ORCPT ); Fri, 31 Dec 2010 06:47:58 -0500 Message-ID: <4D1DC2DD.6050400@infradead.org> Date: Fri, 31 Dec 2010 09:47:41 -0200 From: Mauro Carvalho Chehab User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Laurent Pinchart CC: "Igor M. Liplianin" , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, aospan@netup.ru Subject: Re: [PATCH 01/18] Altera FPGA firmware download module. References: <201012310726.31851.liplianin@netup.ru> <201012311212.19715.laurent.pinchart@ideasonboard.com> <4D1DBE2A.5080003@infradead.org> <201012311230.51903.laurent.pinchart@ideasonboard.com> In-Reply-To: <201012311230.51903.laurent.pinchart@ideasonboard.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1922 Lines: 51 Em 31-12-2010 09:30, Laurent Pinchart escreveu: > Hi Mauro, > > On Friday 31 December 2010 12:27:38 Mauro Carvalho Chehab wrote: >> Em 31-12-2010 09:12, Laurent Pinchart escreveu: >>> Hi Igor, >>> >>> On Friday 31 December 2010 06:26:31 Igor M. Liplianin wrote: >>>> It uses STAPL files and programs Altera FPGA through JTAG. >>>> Interface to JTAG must be provided from main device module, >>>> for example through cx23885 GPIO. >>> >>> It might be a bit late for this comment (sorry for not having noticed the >>> patch set earlier), but... >>> >>> Do we really need a complete JTAG implementation in the kernel ? Wouldn't >>> it better to handle this in userspace with a tiny kernel driver to >>> access the JTAG signals ? >> >> Laurent, >> >> Igor already explained it. From what I understood, the device he is >> working has a firmware that needs to be loaded via JTAG/FPGA. > > I understand this. However, a complete JTAG state machine in the kernel, plus > an Altera firmware parser, seems to be a lot of code that could live in > userspace. Moving it to userspace would mean a kernel driver that would depend on an userspace daemon^Wfirmware loader to work. I would NAK such designs. The way it is is fine from my POV. >> Actually, I liked the idea, as the FPGA programming driver could be >> useful if other drivers have similar usecases. > > If I understand it correctly the driver assumes the firmware is in an Altera > proprietary format. If we really want JTAG code in the kernel we should at > least split the file parser and the TAP access code. > Agreed, but I don't think this would be a good reason to block the code merge for .38. 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/