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 8E22C8E2 for ; Tue, 27 Jun 2017 11:50:23 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 20CC418D for ; Tue, 27 Jun 2017 11:50:23 +0000 (UTC) Date: Tue, 27 Jun 2017 13:41:22 +0200 From: Sebastian Reichel To: Mark Brown Message-ID: <20170627114122.glrzwray6oi34jla@earth> References: <20170625104850.GA24717@amd> <20170626105451.tv4k7ib2g2kiknah@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="z2kmqv7lcc5bwupr" Content-Disposition: inline In-Reply-To: <20170626105451.tv4k7ib2g2kiknah@sirena.org.uk> Cc: ksummit-discuss@lists.linuxfoundation.org, Pavel Machek Subject: Re: [Ksummit-discuss] [TECH TOPIC] mobile phones List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --z2kmqv7lcc5bwupr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Jun 26, 2017 at 11:54:51AM +0100, Mark Brown wrote: > On Sun, Jun 25, 2017 at 12:48:50PM +0200, Pavel Machek wrote: >=20 > > 2) How to handle GSM audio? >=20 > Do you have some more specific concern? This already works basically > fine upstream, we happily support off-SoC audio paths. The digital > configuration could do with being more flexible but it works and people > ship it. It would be awfully nice to have some control/visibility of > the modem side but that's just a missing driver problem. This is not a general problem, but only with the Nokia phones, which sends raw audio data to the CPU. Nokia's userspace did postprocessing on DSP and then played the audio via pulseaudio. As you mentioned this requires a low latency setup of ~20ms. @Pavel: The Nokia phones are the only ones I'm aware of, that are implemented this way. Basically all other phones provide a normal digital audio interface. On those systems you only have to configure soundcard correctly and will have working audio. And as Mark mentioned modern 4G basically uses VoIP, so if some vendor decides to drop audio handling from modem again it can simply be done in userspace using normal VoIP application. -- Sebastian --z2kmqv7lcc5bwupr Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAllSRF4ACgkQ2O7X88g7 +ppdig//RmGTHDU3PUe3OxKUHlApPRGfUicvKn+s0yWwiuRcS4dvfipDgh90WRZU I7uN+QgJx9EsCGj0xuviV+c8gAifSUZfA/GjqJcymMctl+IA1L2h7vUJFVrql9dk klj+n2gfhjD8caD8UJRB+SHnnuWnycF3SgxRmictXZlW6Us3iQetnMNWiTlvPKm3 CCac/ddPs7wtARorUsm2PTxbWzvgYvhthq3UVZ8HY8LQRVL4h8iMQLAX4PYrp/zb 6na13bAsFec3FVCpHD78Cd/5jgZznq22yQm1Hn0tpNXiIcCasbIzi3v/e3cmArrs gpGzdhozX6Fwn14uQa+0yVbKCZbkma+eO9AcYCb4kKKh+BvHfsRv9XcCJ8tFnNQ3 Vr8PvC2t6cDkeOGAFEucgrsnRdD+uKa6+w2HSl7SgOaYSxgM4WmsJILJfDvaogan PLM4fo/lPPgKXaAgZWw2XRcoRV+1YOP4DId+3PLT76m5uxAzf5yZxUuPWimvpZWG cq2CrlP0FgI+Ou5e6AHtKkoKDtRIvoFuWFsWh/5EPEe3DU1EzjTDMOV0Bn4C6NlW FE/g9svzUNwzpQkfHAPZb6hg/svkTvzK1gVmAlVTW2z7Thr0+Lb+I92bVCqZS52y jImtCqYoefYiPT2j89OP191n2OAYFVxyuWva/XlNlpXHYfpJYF8= =hoN8 -----END PGP SIGNATURE----- --z2kmqv7lcc5bwupr--