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 B87646C for ; Sun, 2 Jul 2017 12:03:24 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5DB02A7 for ; Sun, 2 Jul 2017 12:03:24 +0000 (UTC) Date: Sun, 2 Jul 2017 14:03:21 +0200 From: Sebastian Reichel To: Pavel Machek Message-ID: <20170702120321.tskgcrbfehg4fccx@earth> References: <20170626111207.GA11688@amd> <20170626114931.GG23064@atomide.com> <20170626131401.GA11980@amd> <20170626134904.GH23064@atomide.com> <20170626204932.GA19396@amd> <20170627071835.GJ23064@atomide.com> <20170627121455.tljtekx6bmzlezxa@earth> <20170627215727.GA5250@amd> <20170628160112.ip2ambkzlkkoz2ww@earth> <20170628202722.GC18101@amd> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3whyfooflsfv7zxc" Content-Disposition: inline In-Reply-To: <20170628202722.GC18101@amd> Cc: ksummit-discuss@lists.linuxfoundation.org Subject: Re: [Ksummit-discuss] [TECH TOPIC] mobile phones List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --3whyfooflsfv7zxc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Wed, Jun 28, 2017 at 10:27:22PM +0200, Pavel Machek wrote: > > > Oh, another major piece is DSP coprocessor that is there. Unlike > > > graphics, we don't even know how support for it should like. > >=20 > > https://www.kernel.org/doc/Documentation/remoteproc.txt > >=20 > > config OMAP_REMOTEPROC > > tristate "OMAP remoteproc support" > > [...] > > help > > Say y here to support OMAP's remote processors (dual M3 > > and DSP on OMAP4) via the remote processor framework. > >=20 > > Currently only supported on OMAP4. > >=20 > > Usually you want to say Y here, in order to enable multimedia > > use-cases to run on your platform (multimedia codecs are > > offloaded to remote DSP processors using this framework). > >=20 > > It's safe to say N here if you're not interested in multimedia > > offloading or just want a bare minimum kernel. > >=20 > > I have been told by some Nokia people (I do not remember who it > > was, possibly Sakari), that the DSP is not that powerful and any > > calculation should also be possible on CPU (wasting a bit of > > energy). >=20 > Ok, we probably don't care about DSP, but lets say we had really > fast DSP or really cared about power. >=20 > We'd need remoteproc. Sure. But that has no interface for userland, > right? remoteproc is only for start/stop + fw loading. The actual communication is done using rpmsg, which does not yet have a userspace API afaik. > So we'd need to introduce interface for userland... fine. >=20 > And then we'd need cross-compilers for the DSP used. Ok. Yes. As far as I know there is currently no open source toolchain for the TI DSP. > And then we'd need to split mpg123 to CPU and DSP parts, and modify it > so that it can run the DSP parts using remoteproc, when available? >=20 > That starts to be ... complex, with changes all over the system :-(. With little gain expected on N900... -- Sebastian --3whyfooflsfv7zxc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAllY4QYACgkQ2O7X88g7 +pqmJQ//SmQF7+D4JbzxQEioTVwAGm8jRUoycgE+ls3gLXvsWlyDcFz93Jy0O4d7 YquD+p+XBIfaxj8R0NFOcDdZyrU0RMynn7+HUhJPH07cMdTCESHpSjZJT2Ol/UBe +fyjAvzKiPMRjJKAiQMsXu9VzFHdaV5Z7hsTJmWIMNwyQLgyDTQFCbFDpU2NXD8p v2ES033XnmPelbTXujK7ysAbd5vkkkTlIQDJC2d5x63d0l4iH484oRgUMWl2rfNq erjDBNQ6+6z2FSPZ4xotO5Al5Wy713vv/RB0F/j9MQJD0e2gymQI9EQGuZ5dJuIh RgCC2XYTIJ63txl2WgKT0AGJizp9AcIIkDKjtM8grlvZpYO2pulZGESqp2Mo8Z5g RzH8Ewshu2S6PSyjNshZgrNmCTBf9zhA847VEqOT6OoKRkSyu9atYwwV5uEVWLYC ESaKn5Ogk2OqJJK9ZKNePxQXkE87FS4pYddKb1TvWtfEFF3tZPIa5GzV6j/lO7Ft 4kDQ/dkkISfTwBS0dRgogcV1K68pf6Dgo1YBWlEKhYWvMg8nBCFwcuRlGmAl8KGM unkzwJ4fe5wkyq0s2we9AlxKB8M/wAUxXJuzZ3/1y3KeAIz29JwqHr2yGPBuS2y1 pTvbX8MnMsTUshjGXXjAKa1G0RYqTKJ9ZA9WYf4elBynC4VSOJs= =TjVX -----END PGP SIGNATURE----- --3whyfooflsfv7zxc--