Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758555AbaGARsI (ORCPT ); Tue, 1 Jul 2014 13:48:08 -0400 Received: from smtp6-g21.free.fr ([212.27.42.6]:38037 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758493AbaGARsE convert rfc822-to-8bit (ORCPT ); Tue, 1 Jul 2014 13:48:04 -0400 Date: Tue, 1 Jul 2014 19:49:53 +0200 From: Jean-Francois Moine To: Russell King - ARM Linux Cc: Sebastian Hesselbarth , Gregory Clement , Andrew Lunn , Jason Cooper , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] ARM: mvebu: add armada drm init to Dove board setup Message-ID: <20140701194953.78a0c5cf@armhf> In-Reply-To: <20140701164527.GY32514@n2100.arm.linux.org.uk> References: <1404219871-18419-1-git-send-email-sebastian.hesselbarth@gmail.com> <1404219871-18419-5-git-send-email-sebastian.hesselbarth@gmail.com> <20140701131026.GO32514@n2100.arm.linux.org.uk> <53B2B5E5.50502@gmail.com> <20140701133627.GP32514@n2100.arm.linux.org.uk> <20140701180426.54a79a0b@armhf> <20140701164527.GY32514@n2100.arm.linux.org.uk> X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.24; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Jul 2014 17:45:27 +0100 Russell King - ARM Linux wrote: > Let's tell the full story rather than just presenting half of it. > > You indeed wanted to do what you said above, but you also wanted to > completely change the component helpers in a way that I was not happy > with. You wanted to add all sorts of DT specific gunk into the > helpers, which would have tied it to DT. > > While DT is the current thing on ARM, it is /not/ the current thing > everywhere - a point which you failed to grasp. I don't think that there will ever be a x86 DT. Yes, I did not know what was the DT. For me, when entering in the ARM world, it was a marvellous tool which could have ended in a unique ARM kernel. I'm a dreamer! > You wanted to make the component operations optional, which I pointed > out makes no sense (because then components have no way to know what > happens to their master device - which is /really/ important for DRM.) You did not explain too much that you wanted to keep it for DRM only. > You refused to listen to those concerns, and refused to look at the > patch which I proposed, which did exactly the same as your patch, > while keeping the DRM slave interfaces for tilcdc to use, until they > have a chance to convert over. The change in tilcdc was easy and the code was greatly simplified. > You kept telling me that I had "opened the door" to your changes. I > claimed that your changes abused the code which I had written - a point > which I still maintain to this day. Your code was offering a simple way to synchronize the system initialization without this lot of 'probe defer's. It could have been used so. > You also claimed that deferred probing didn't work. Since the component > helpers were designed with the deferred probing problem in mind at the > time, and include the solution to that problem - which has been well > tested hundreds if not thousands of times by now - and you did not > provide the technical details as to why you thought it didn't work, > there was nothing that could be done to progress that point. AFAIR, you also said that the probe defer was not working. But, thanks again for your component layer: all my init problems are gone, even if there are still some prove defer's... > Moreover, your abuse of the component layer would have made it more > difficult to maintain it into the future - which is a fundamental > point which has to be considered when accepting any patch into the > kernel. If a patch makes some code unable to be maintained, then an > alternative approach has to be found. Since you were not willing to > compromise on finding or considering alternative approaches such as > the one I presented. I don't see what you are talking about. > Since the component layer had had various comments which were in > progress, and your abuse of the component layer would have also > prevented those changes taking place (which are - in part - the set > of component patches which are on the list now) there is no way that > your uncompromising set of patches would be merged - at least not > until you start accepting some of the comments being given to you. > > > Now, the last thing for me is to put the TDA998x codec in the kernel > > (it is also working in an other machine with 2 tda998x's). > > Yes, supporting the I2S connection is something that is need, but we > /also/ need to support SPDIF, and SPDIF is the preferred method on > the Cubox. SPDIF should be used to talk to the TDA998x whenever > possible because it opens up the possibility for sending out > compressed MPEG2 and AC-3 audio streams, thus offloading the decode > of these formats to external hardware. > > This works today, and is a feature that people have been using with > platforms such as xbmc and various other installations on the Cubox. > > Limiting to I2S means that you can't send out these compressed audio > streams. In fact, the Dove manual tells you that you must disable > the I2S playback stream if you're sending non-PCM - non-PCM is only > supported via SPDIF. I don't understand: both I2S and S/PDIF may work in the kirkwood audio subsystem as it is (yes, actually not at the same time, and this is a choice because DPCM does not work for the Cubox). I have the 3 ways in my system: $ cat /proc/asound/pcm 00-00: i2s-i2s-hifi i2s-hifi-0 : : playback 1 00-01: spdif-spdif-hifi spdif-hifi-1 : : playback 1 00-02: spdif-dit-hifi dit-hifi-2 : : playback 1 So, S/PDIF should work, but I don't know it: I have no optical connector. -- Ken ar c'hentaƱ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ -- 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/