From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH v8 2/4] fpga manager: add sysfs interface document Date: Tue, 13 Jan 2015 08:28:57 +0100 Message-ID: <20150113072857.GA11760@amd> References: <1420575219-27061-1-git-send-email-atull@opensource.altera.com> <1420575219-27061-3-git-send-email-atull@opensource.altera.com> <20150107084819.GA1887@amd> <20150109205643.GA5761@amd> <4D4EA2D5-68DD-49F7-9E2D-3A0A8F6AF9CA@konsulko.com> <20150110151118.GA16036@amd> <20150112084530.GA28681@amd> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" To: Michal Simek Cc: mark.rutland@arm.com, linux-doc@vger.kernel.org, rubini@gnudd.com, Pantelis Antoniou , hpa@zytor.com, Steffen Trumtrar , devel@driverdev.osuosl.org, sameo@linux.intel.com, nico@linaro.org, ijc+devicetree@hellion.org.uk, kyle.teske@ni.com, jgunthorpe@obsidianresearch.com, Grant Likely , davidb@codeaurora.org, Linus Walleij , cesarb@cesarb.net, devicetree@vger.kernel.org, jason@lakedaemon.net, pawel.moll@arm.com, iws@ovro.caltech.edu, atull , Mark Brown , philip@balister.org, dinguyen@opensource.altera.com, Michal Simek , Greg Kroah-Hartman , yvanderv@opensource.altera.com, Linux Kernel Mailing List , Felipe Balbi List-Id: devicetree@vger.kernel.org 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). 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. Thanks, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html