Return-path: Received: from mga02.intel.com ([134.134.136.20]:55318 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753361Ab3HWJsB convert rfc822-to-8bit (ORCPT ); Fri, 23 Aug 2013 05:48:01 -0400 From: "Rymarkiewicz, WaldemarX" To: Lars Poeschel CC: Lars Poeschel , "sameo@linux.intel.com" , "jslaby@suse.cz" , "linux-kernel@vger.kernel.org" , "linux-wireless@vger.kernel.org" , "linux-nfc@lists.01.org" Subject: RE: [linux-nfc] [PATCH RFC] nfc: add a driver for pn532 connected on uart Date: Fri, 23 Aug 2013 09:47:57 +0000 Message-ID: (sfid-20130823_114825_358235_B720103B) References: <1377181699-1668-1-git-send-email-larsi@wh2.tu-dresden.de> <201308231128.47731.poeschel@lemonage.de> In-Reply-To: <201308231128.47731.poeschel@lemonage.de> Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, >Yes, I know that and I explicitly mentioned that. I had to get this chip working >somehow and I had to begin somewhere. The pn533 driver is really very hard >to understand with it's massive use of nested callbacks, workqueues and >usb urbs. So I took the approach to try to understand what happens while modifying >and would then later factor out what both drivers have in common. >The other way is understanding the code first and then decide what would be needed for > both chips, factor that out and then write the pn532 uart specific stuff. And this uart stuff >is a pain itself in linux. This way seemed much harder to me, > especially as I have no pn533 device to test which things will break. I understand. It took me some time to understand this too. Now, it's even harder after adding protocol ops, but still is pretty well layered. > I suggest to separate transport layer from the core in pn533 and add > support for uart and usb separately. This is exactly what I've planned > while changing pn533 to support acr122 device. >> Yes, I agree with you this should be done. I'll expect it to be challenging >> but based on my previous work this could be doable. Be sure there will be pitfalls separating transport. I've already experienced some of them adding support for acr122. >> I'll look into that in my next free timeslot. I'll not be able to do that in the next two months. >>Sorry. No worries. I know this pain :) Thanks, /Waldek