From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46C0AEB64D9 for ; Wed, 14 Jun 2023 07:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243075AbjFNHFv (ORCPT ); Wed, 14 Jun 2023 03:05:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242890AbjFNHFM (ORCPT ); Wed, 14 Jun 2023 03:05:12 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC6201FCB; Wed, 14 Jun 2023 00:04:57 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 743121FDE2; 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Wed, 14 Jun 2023 07:04:56 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id gdv7B5hmiWSMEAAAMHmgww (envelope-from ); Wed, 14 Jun 2023 07:04:56 +0000 Date: Wed, 14 Jun 2023 09:04:55 +0200 Message-ID: <87edmebk2w.wl-tiwai@suse.de> From: Takashi Iwai To: Srinivas Kandagatla Cc: vkoul@kernel.org, broonie@kernel.org, tiwai@suse.com, corbet@lwn.net, alsa-devel@alsa-project.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, quic_plai@quicinc.com, quic_mohs@quicinc.com Subject: Re: [PATCH v2] ALSA: compress: allow setting codec params after next track In-Reply-To: <20230609150416.24525-1-srinivas.kandagatla@linaro.org> References: <20230609150416.24525-1-srinivas.kandagatla@linaro.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, 09 Jun 2023 17:04:16 +0200, Srinivas Kandagatla wrote: > > For gapless playback it is possible that each track can have different > codec profile with same decoder, for example we have WMA album, > we may have different tracks as WMA v9, WMA v10 and so on > > Or if DSP's like QDSP have abililty to switch decoders on single stream > for each track, then this call could be used to set new codec parameters. > > Existing code does not allow to change this profile while doing gapless > playback. > > Reuse existing SNDRV_COMPRESS_SET_PARAMS to set this new track params along > some additional checks to enforce proper state machine. > > With this new changes now the user can call SNDRV_COMPRESS_SET_PARAMS > anytime after setting next track and additional check in write should > also ensure that params are set before writing new data. > > Signed-off-by: Srinivas Kandagatla > --- > Changes since v1/RFC: > - removed introduction of new IOCTL, as suggested. > - update the state-machine doc. > > .../sound/designs/compress-offload.rst | 52 +++++++++---------- > sound/core/compress_offload.c | 10 ++-- > 2 files changed, 33 insertions(+), 29 deletions(-) > > diff --git a/Documentation/sound/designs/compress-offload.rst b/Documentation/sound/designs/compress-offload.rst > index 935f325dbc77..205cadcabe70 100644 > --- a/Documentation/sound/designs/compress-offload.rst > +++ b/Documentation/sound/designs/compress-offload.rst > @@ -256,32 +256,32 @@ Gapless Playback SM > For Gapless, we move from running state to partial drain and back, along > with setting of meta_data and signalling for next track :: > > - > - +----------+ > - compr_drain_notify() | | > - +------------------------>| RUNNING | > - | | | > - | +----------+ > - | | > - | | > - | | compr_next_track() > - | | > - | V > - | +----------+ > - | | | > - | |NEXT_TRACK| > - | | | > - | +----------+ > - | | > - | | > - | | compr_partial_drain() > - | | > - | V > - | +----------+ > - | | | > - +------------------------ | PARTIAL_ | > - | DRAIN | > - +----------+ > + +----------+ > + compr_drain_notify() | | compr_set_params() iff next-track set. > + +------------------------>| RUNNING |----------------------+ > + | | | | > + | +----------+ | > + | | | > + | | | > + | | compr_next_track() | > + | | V > + | V | > + | +----------+ | > + | | | | > + | |NEXT_TRACK| | > + | | | | > + | +----------+ | > + | | | > + | +----------------------------+ > + | | > + | | compr_partial_drain() > + | | > + | V > + | +----------+ > + | | | > + +------------------------ | PARTIAL_ | > + | DRAIN | > + +----------+ > > Not supported > ============= > diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c > index 243acad89fd3..fe67228e74b3 100644 > --- a/sound/core/compress_offload.c > +++ b/sound/core/compress_offload.c > @@ -294,6 +294,9 @@ static ssize_t snd_compr_write(struct file *f, const char __user *buf, > case SNDRV_PCM_STATE_SETUP: > case SNDRV_PCM_STATE_PREPARED: > case SNDRV_PCM_STATE_RUNNING: > + /* Make sure next track params are set before writing new data */ > + if (stream->next_track) > + return -EPERM; Hm, does this logic correctly match with the comment above? Also, this misses the mutex unlock. thanks, Takashi