From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754973AbcBZUIt (ORCPT ); Fri, 26 Feb 2016 15:08:49 -0500 Received: from lists.s-osg.org ([54.187.51.154]:45174 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbcBZUIs (ORCPT ); Fri, 26 Feb 2016 15:08:48 -0500 Subject: Re: [PATCH v3 22/22] sound/usb: Use Media Controller API to share media resources To: Takashi Iwai References: <0822f80e0acc5119e6f6deccf002ccadeb3b145b.1455233156.git.shuahkh@osg.samsung.com> Cc: hans.verkuil@cisco.com, laurent.pinchart@ideasonboard.com, clemens@ladisch.de, sakari.ailus@linux.intel.com, javier@osg.samsung.com, mchehab@osg.samsung.com, geliangtang@163.com, alsa-devel@alsa-project.org, arnd@arndb.de, ricard.wanderlof@axis.com, labbott@fedoraproject.org, chehabrafael@gmail.com, klock.android@gmail.com, misterpib@gmail.com, prabhakar.csengg@gmail.com, ricardo.ribalda@gmail.com, ruchandani.tina@gmail.com, takamichiho@gmail.com, tvboxspy@gmail.com, dominic.sacre@gmx.de, albert@huitsing.nl, crope@iki.fi, julian@jusst.de, pierre-louis.bossart@linux.intel.com, corbet@lwn.net, joe@oampo.co.uk, johan@oljud.se, dan.carpenter@oracle.com, pawel@osciak.com, p.zabel@pengutronix.de, perex@perex.cz, stefanr@s5r6.in-berlin.de, inki.dae@samsung.com, j.anaszewski@samsung.com, jh1009.sung@samsung.com, k.kozlowski@samsung.com, kyungmin.park@samsung.com, m.szyprowski@samsung.com, nenggun.kim@samsung.com, sw0312.kim@samsung.com, elfring@users.sourceforge.net, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linuxbugs@vittgam.net, gtmkramer@xs4all.nl, normalperson@yhbt.net, daniel@zonque.org From: Shuah Khan Organization: Samsung Open Source Group Message-ID: <56D0B0CB.8060709@osg.samsung.com> Date: Fri, 26 Feb 2016 13:08:43 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/26/2016 12:55 PM, Takashi Iwai wrote: > On Fri, 12 Feb 2016 00:41:38 +0100, > Shuah Khan wrote: >> >> Change ALSA driver to use Media Controller API to >> share media resources with DVB and V4L2 drivers >> on a AU0828 media device. Media Controller specific >> initialization is done after sound card is registered. >> ALSA creates Media interface and entity function graph >> nodes for Control, Mixer, PCM Playback, and PCM Capture >> devices. >> >> snd_usb_hw_params() will call Media Controller enable >> source handler interface to request the media resource. >> If resource request is granted, it will release it from >> snd_usb_hw_free(). If resource is busy, -EBUSY is returned. >> >> Media specific cleanup is done in usb_audio_disconnect(). >> >> Signed-off-by: Shuah Khan >> --- >> sound/usb/Kconfig | 4 + >> sound/usb/Makefile | 2 + >> sound/usb/card.c | 14 +++ >> sound/usb/card.h | 3 + >> sound/usb/media.c | 318 +++++++++++++++++++++++++++++++++++++++++++++++ >> sound/usb/media.h | 72 +++++++++++ >> sound/usb/mixer.h | 3 + >> sound/usb/pcm.c | 28 ++++- >> sound/usb/quirks-table.h | 1 + >> sound/usb/stream.c | 2 + >> sound/usb/usbaudio.h | 6 + >> 11 files changed, 448 insertions(+), 5 deletions(-) >> create mode 100644 sound/usb/media.c >> create mode 100644 sound/usb/media.h >> >> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig >> index a452ad7..ba117f5 100644 >> --- a/sound/usb/Kconfig >> +++ b/sound/usb/Kconfig >> @@ -15,6 +15,7 @@ config SND_USB_AUDIO >> select SND_RAWMIDI >> select SND_PCM >> select BITREVERSE >> + select SND_USB_AUDIO_USE_MEDIA_CONTROLLER if MEDIA_CONTROLLER && MEDIA_SUPPORT > > Looking at the media Kconfig again, this would be broken if > MEDIA_SUPPORT=m and SND_USB_AUDIO=y. The ugly workaround is something > like: > select SND_USB_AUDIO_USE_MEDIA_CONTROLLER \ > if MEDIA_CONTROLLER && (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND) My current config is MEDIA_SUPPORT=m and SND_USB_AUDIO=y It is working and I didn't see any issues so far. Maybe the current change is good. I am hoping kbuild-bot can find issues (if any) once it gets merged. > > Other than that, it looks more or less OK to me. > The way how media_stream_init() gets called is a bit worrisome, but it > should work practically. Another concern is about the disconnection. > Can all function calls in media_device_delete() be safe even if it's > called while the application still opens the MC device? Right. I have been looking into device removal path when ioctls are active and I can resolve any issues that might surface while an audio app is active when device is removed. > > In anyway, such a thing can be improved later once after we get this > merged, too. So, feel fee to take my ack. > > Acked-by: Takashi Iwai thanks for the Ack -- Shuah > > > thanks, > > Takashi > -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shuahkh@osg.samsung.com | (970) 217-8978