From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [RFC PATCH v8 1/4] media: Media Device Allocator API Date: Sun, 9 Dec 2018 09:09:44 +0100 Message-ID: <20181209080944.GA7561@amd> References: <20181119085931.GA28607@amd> <73c22137-9c7a-75c8-8cd1-3736c63c2d40@kernel.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============9160131784896991348==" Return-path: Received: from atrey.karlin.mff.cuni.cz (atrey.karlin.mff.cuni.cz [195.113.26.193]) by alsa0.perex.cz (Postfix) with ESMTP id 3588126796C for ; Sun, 9 Dec 2018 09:09:45 +0100 (CET) In-Reply-To: <73c22137-9c7a-75c8-8cd1-3736c63c2d40@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: shuah Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, tiwai@suse.com, mchehab@kernel.org, linux-media@vger.kernel.org List-Id: alsa-devel@alsa-project.org --===============9160131784896991348== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="n8g4imXOkfNTN/H1" Content-Disposition: inline --n8g4imXOkfNTN/H1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu 2018-12-06 08:33:14, shuah wrote: > On 11/19/18 1:59 AM, Pavel Machek wrote: > >On Thu 2018-11-01 18:31:30, shuah@kernel.org wrote: > >>From: Shuah Khan > >> > >>Media Device Allocator API to allows multiple drivers share a media dev= ice. > >>Using this API, drivers can allocate a media device with the shared str= uct > >>device as the key. Once the media device is allocated by a driver, other > >>drivers can get a reference to it. The media device is released when all > >>the references are released. > > > >Sounds like a ... bad idea? > > > >That's what new "media control" framework is for, no? > > > >Why do you need this? >=20 > Media control framework doesn't address this problem of ownership of the > media device when non-media drivers have to own the pipeline. In this cas= e, > snd-usb owns the audio pipeline when an audio application is using the > device. Without this work, media drivers won't be able to tell if snd-usb= is > using the tuner and owns the media pipeline. >=20 > I am going to clarify this in the commit log. I guess I'll need the explanation, yes. How can usb soundcard use the tuner? I thought we'd always have userspace component active and moving data between tuner and usb sound card? Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --n8g4imXOkfNTN/H1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlwMzcgACgkQMOfwapXb+vIQkwCfboSZoTYly+FjJatgpBdS3bHX VlQAn2u6XZ6zbrSsLhKe0NfdcDjS6o4Q =rWVL -----END PGP SIGNATURE----- --n8g4imXOkfNTN/H1-- --===============9160131784896991348== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============9160131784896991348==--