From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 8C7E8410 for ; Tue, 20 Oct 2015 13:13:53 +0000 (UTC) Received: from mezzanine.sirena.org.uk (mezzanine.sirena.org.uk [106.187.55.193]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 4FAA6151 for ; Tue, 20 Oct 2015 13:13:42 +0000 (UTC) Date: Tue, 20 Oct 2015 14:13:30 +0100 From: Mark Brown To: Mauro Carvalho Chehab Message-ID: <20151020131330.GY32054@sirena.org.uk> References: <20151012190137.GA1992@thunk.org> <20151019103304.27e596a5@recife.lan> <20151019135348.GH14956@sirena.org.uk> <1445272076.2481.37.camel@loki> <20151019173419.042d5e8b@recife.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qwWC3uIwaXcGNtT+" Content-Disposition: inline In-Reply-To: <20151019173419.042d5e8b@recife.lan> Cc: Liam Girdwood , Lars-Peter Clausen , Mark Brown , ksummit-discuss@lists.linuxfoundation.org Subject: Re: [Ksummit-discuss] Draft agenda for the kernel summit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --qwWC3uIwaXcGNtT+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Oct 19, 2015 at 05:34:19PM -0200, Mauro Carvalho Chehab wrote: > Liam Girdwood escreveu: > > Having a simple mechanism for dumping topology data is important as we > > will need to be able to easily dump this data on Android and Chrome > > alongside regular Linux for development and debug purposes. i.e. > > cat /sys/some/dump/file > audio_topology > Well, it is not hard to get the topology using the media controller. > I wrote a testing program using it at: > http://git.linuxtv.org/cgit.cgi/mchehab/experimental-v4l-utils.git/tree/contrib/test/mc_nextgen_test.c > The only library optional dependency is libudev, used to get the > device node names. The code falls back to use /sys/dev/char/ and > /dev to find the device names when compiled without libudev. > So, it should be easy to provide a cat-like program that would be > dumping the audio topology on some file. It's still a program that has to be built for and installed on the device under test which is the big bar for a lot of users (consider the case where an audio expert is doing system tuning on a device using a firmware image supplied from elsewhere, it may be difficult for them to build new programs for the image or request that they be included in the image). > > What I'd like to propose is that we support both mechanisms for dumping > > the audio topology data. :- > > 1) Simple file dump using same format that topology is loaded. Used by > > kernel/firmware developers only when media controller userspace not > > available. Enabled by kernel Kconfig debug option. > Yeah, it sounds reasonable to have a mechanism like that just for > debug purposes. > > 2) Media controller API used by everyone else. > Makes sense to me. My main concern here is ending up with two different machine parsable formats for exporting the topology information to userspace - it's potentially a bit confusing for people to know which one to pick and might end up needing multiple tools and libraries to parse depending on the situation. It would be much nicer if we could get a consistent format between the two. --qwWC3uIwaXcGNtT+ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWJj35AAoJECTWi3JdVIfQyjkH/2dEAAATgmzjNOfD2eRuGFhk MDUBMsdqsK71ofzhtdKuIWgs2o2DUvZeelilzNV35ABjQklvvg59rbwOFhuJCD4j 0LPQTlQ/8FybZYmRSxjFu9LEz3yMnBwQhy8bmwrqlCuBwVWFHGai9EuglDLzK9+V vzGnFRKm/y6uN3Vhk9VjSawOQx0sidsrrOsxEP5gvx2T0pSKtPnYl+OgPbpo55ct cGFcx7MZZebBobYsx5Lc6PmKcgaqmAKqRBPbu1dgm1G8S3g2XAlhF11RywQOtF5V WgunQMCY7FhsBAdi5q5UbXb+K9X0Pk6HbqJHCNqoDGxqoUd52uZbx+MbwSu2BT8= =baWN -----END PGP SIGNATURE----- --qwWC3uIwaXcGNtT+--