From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751481AbbAMH45 (ORCPT ); Tue, 13 Jan 2015 02:56:57 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:52622 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750963AbbAMH4z (ORCPT ); Tue, 13 Jan 2015 02:56:55 -0500 Date: Tue, 13 Jan 2015 08:56:51 +0100 From: Pavel Machek To: Pantelis Antoniou Cc: Michal Simek , atull , Greg Kroah-Hartman , jgunthorpe@obsidianresearch.com, hpa@zytor.com, Michal Simek , rdunlap@infradead.org, Linux Kernel Mailing List , devicetree@vger.kernel.org, robh+dt@kernel.org, Grant Likely , iws@ovro.caltech.edu, linux-doc@vger.kernel.org, Mark Brown , philip@balister.org, rubini@gnudd.com, Steffen Trumtrar , jason@lakedaemon.net, kyle.teske@ni.com, nico@linaro.org, Felipe Balbi , m.chehab@samsung.com, davidb@codeaurora.org, Rob Landley , davem@davemloft.net, cesarb@cesarb.net, sameo@linux.intel.com, akpm@linux-foundation.org, Linus Walleij , pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devel@driverdev.osuosl.org, Alan Tull , dinguyen@opensource.altera.com, yvanderv@opensource.altera.com Subject: Re: [PATCH v8 2/4] fpga manager: add sysfs interface document Message-ID: <20150113075651.GB11760@amd> References: <20150107084819.GA1887@amd> <20150109205643.GA5761@amd> <4D4EA2D5-68DD-49F7-9E2D-3A0A8F6AF9CA@konsulko.com> <20150110151118.GA16036@amd> <20150112084530.GA28681@amd> <20150113072857.GA11760@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2015-01-13 09:40:18, Pantelis Antoniou wrote: > Hi Pavel, > > > On Jan 13, 2015, at 09:28 , Pavel Machek wrote: > > > > Hi! > > > >>>>>>>>>> +What: /sys/class/fpga_manager//firmware > >>>>>>>>>> +Date: October 2014 > >>>>>>>>>> +KernelVersion: 3.18 > >>>>>>>>>> +Contact: Alan Tull > >>>>>>>>>> +Description: Name of the FPGA image file to load using firmware > >>>>>>>>>> class. > >>>>>>>>> > >>>>>>>>> This one is ugly: it unneccessarily passes firmware name through the > >>>>>>>>> kernel. Just make interface and code simpler by always passing > >>>>>>>>> "socfpga-fpga-image" or something like that. > > ... > > > >>> What is cumbersome about symlink? Why is "fake" symlink in sysfs better? > >>> > >>>> Previous uses of the firmware layer has been to use it to load once after > >>>> bootup; this is different since some use cases will want to switch out > >>>> the FPGA image. If someone wants there to be only one FPGA image on > >>>> the FGPA forever, they will probably not be using this framework; their > >>>> FPGA will probably be loaded before Linux boots up. > >>> > >>> Why? I have just one image on the fpga, and would prefer to load it > >>> from Linux. > >> > >> Pavel: These patches target staging and sysfs interface doesn't need to be stable > >> at this time. I would prefer to add these patches to staging for 3.20 > >> and feel free to send the patch which fix this. > > > > Interesting way to address patch review. "We'll merge it, and you can > > fix it up later". > > > >> With your code will be exactly clear how you want to use it and we can > >> talk about it. > > > > I'm pretty sure Alan knows what I want at this point, he just does not > > want to do it. > > > > For the record, I want to drop "firmware" file, use fixed firmware > > name, and deal with multiple firmwares in userspace (using symlink or > > udev magic). > > That’s completely bogus. Using a fixed firmware file does not respond to > real world usage, and there are no words to describe the hacks using > symlinks and udev in an embedded product. > > I believe this is simplest solution, should be adequate, and is > > certainly less ugly than implementing fake symlink in > > /sys/.../firmware. And I have yet to hear what is wrong with that > > suggestion. > > Everything. Can you be more specific? Current solution already has a fake symlink, implemented badly. Just remove it, and use real symlink (and then you can optionally think of something better...) Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html