Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751334AbdFYQjq (ORCPT ); Sun, 25 Jun 2017 12:39:46 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:34259 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751157AbdFYQjo (ORCPT ); Sun, 25 Jun 2017 12:39:44 -0400 MIME-Version: 1.0 In-Reply-To: <1497792234-19802-1-git-send-email-ruslan.bilovol@gmail.com> References: <1497792234-19802-1-git-send-email-ruslan.bilovol@gmail.com> From: Jassi Brar Date: Sun, 25 Jun 2017 22:09:42 +0530 Message-ID: Subject: Re: [PATCH v5 0/4] USB Audio Gadget refactoring To: Ruslan Bilovol Cc: Felipe Balbi , Daniel Mack , Clemens Ladisch , Jonathan Corbet , Greg Kroah-Hartman , Peter Chen , Julian Scheel , "linux-usb@vger.kernel.org" , linux-doc@vger.kernel.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5302 Lines: 125 On Sun, Jun 18, 2017 at 6:53 PM, Ruslan Bilovol wrote: > Hi Felipe, > > This is v5 of audio gadget refactoring. > Note, that legacy f_uac1 function is broken since v4.10 > by commit 7e4da3fcf7c9 ("usb: gadget: composite: Test > get_alt() presence instead of set_alt()"). The fact that > at v4.12-rc5 time nobody cares about may be a good sign > that number of users is small if any. Thus making it > legacy makes sence. > > This series depends on legacy f_uac1 fix I posted before: > http://www.spinics.net/lists/linux-usb/msg158373.html > Without this fix it's not possible to check that refactoring > didn't break legacy f_uac1 functionality > > ======================================== > > I came to this patch series when wanted to do two things: > - use UAC1 as virtual ALSA sound card on gadget side, > just like UAC2 is used so it's possible to do rate > resampling > - have both playback/capture support in UAC1 > > Since I wanted to have same behavior for both UAC1/UAC2, > obviously I've got an utility part (u_audio.c) for > virtual ALSA sound card handling like we have > for ethernet(u_ether) or serial(u_serial) functions. > Function-specific parts (f_uac1/f_uac2) became almost > as storage for class-specific USB descriptors, some > boilerplate for configfs, binding and few USB > config request handling. > > Originally in RFC [1] I've posted before, there was > major change to f_uac1 after that it couldn't do > direct play to existing ALSA sound card anymore, > representing audio on gadget side as virtual > ALSA sound card where audio streams are simply > sinked to and sourced from it, so it may break > current usecase for some people (and that's why > it was RFC). > > During RFC discussion, it was agreed to not touch > existing f_uac1 implementation and create new one > instead. At v4 patchet discussion another approach > was agreed - current f_uac1.c gets renamed to > f_uac1_legacy.c and introduced a *new* f_uac1.c > instead that is done in current patchset (v5) > > Now, it's possible to use existing user-space > applications for audio routing between Audio Gadget > and real sound card. I personally use alsaloop tool > from alsautils and have ability to create PCM > loopback between two different ALSA cards using > rate resampling, which was not possible with previous > "direct play to ALSA card" approach in f_uac1. > > While here, also dropped redundant platform > driver/device creation in f_uac2 driver (as well as > didn't add "never implemented" volume/mute functionality > in f_uac1_legacy to f_uac1) that made this work even > easier to do. > > This series is tested with both legacy g_audio.ko and > modern configfs approaches under Ubuntu 14.04 (UAC1 and > UAC2) and under Windows7 x64 (UAC1 only) having > perfect results in all cases. > > Comments, testing are welcome. > > v5 changes: > - after discussion with Felipe, switched to another > approach with making current f_uac1 legacy and > introducing a new f_uac1.c instead > - addressed Jassi's copyright comments > > v4 changes: > - renamed f_uac1_newapi to f_uac1_acard that is > more meaningful > - rebased on top of balbi/next > > v3 changes: > - renamed u_audio exported symbols so they don't > conflict with old f_uac1 if both are built-in. > > v2 changes: > - do not touch f_uac1, instead created f_uac1_newapi > - added documentation for f_uac1_newapi > - rebased on top of v4.8-rc1 > > [1] https://lkml.org/lkml/2016/5/23/649 > > Ruslan Bilovol (4): > usb: gadget: f_uac2: remove platform driver/device creation > usb: gadget: f_uac2: split out audio core > usb: gadget: function: make current f_uac1 implementation legacy > usb: gadget: add f_uac1 variant based on a new u_audio api > > Documentation/ABI/testing/configfs-usb-gadget-uac1 | 18 +- > .../ABI/testing/configfs-usb-gadget-uac1_legacy | 12 + > Documentation/usb/gadget-testing.txt | 53 +- > drivers/usb/gadget/Kconfig | 29 +- > drivers/usb/gadget/function/Makefile | 5 +- > drivers/usb/gadget/function/f_uac1.c | 906 +++++++---------- > drivers/usb/gadget/function/f_uac1_legacy.c | 1021 ++++++++++++++++++++ > drivers/usb/gadget/function/f_uac2.c | 795 ++------------- > drivers/usb/gadget/function/u_audio.c | 662 +++++++++++++ > drivers/usb/gadget/function/u_audio.h | 95 ++ > drivers/usb/gadget/function/u_uac1.h | 87 +- > .../gadget/function/{u_uac1.c => u_uac1_legacy.c} | 7 +- > drivers/usb/gadget/function/u_uac1_legacy.h | 82 ++ > drivers/usb/gadget/legacy/Kconfig | 15 +- > drivers/usb/gadget/legacy/audio.c | 55 +- > 15 files changed, 2494 insertions(+), 1348 deletions(-) > create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy > create mode 100644 drivers/usb/gadget/function/f_uac1_legacy.c > create mode 100644 drivers/usb/gadget/function/u_audio.c > create mode 100644 drivers/usb/gadget/function/u_audio.h > rename drivers/usb/gadget/function/{u_uac1.c => u_uac1_legacy.c} (98%) > create mode 100644 drivers/usb/gadget/function/u_uac1_legacy.h > Acked-by: Jassi Brar Thanks.