From patchwork Tue May 2 11:55:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaroslav Kysela X-Patchwork-Id: 678433 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 756F1C77B73 for ; Tue, 2 May 2023 11:57:19 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id EB2671664; Tue, 2 May 2023 13:56:26 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz EB2671664 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1683028637; bh=qCt6kTMLrPY0RGfaN8bBoXmvjbOiugAoHHjEIBcXOEY=; h=From:To:Subject:Date:CC:List-Id:List-Archive:List-Help:List-Owner: List-Post:List-Subscribe:List-Unsubscribe:From; b=LBJYM0JI1SRBADaq4da7YWpv/N81xE50+EQXBVQnq0lwhpnhprekBka2RJdQM0IbG 3O+AWiqGLMiv0gYDBwpcPY1+JyBWPolMrdwgsL4LFooee0yqO/OZuBvc37/FbrVBHT CZnzFCWCAVztdhyhjr3Q1ZNJWf82P/9ObIid2iDA= Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 493B3F8049E; Tue, 2 May 2023 13:56:01 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id D4AFDF8049E; Tue, 2 May 2023 13:55:57 +0200 (CEST) Received: from mail1.perex.cz (mail1.perex.cz [77.48.224.245]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 7BEEFF80114 for ; Tue, 2 May 2023 13:55:55 +0200 (CEST) Received: from mail1.perex.cz (localhost [127.0.0.1]) by smtp1.perex.cz (Perex's E-mail Delivery System) with ESMTP id B736211E2; Tue, 2 May 2023 13:55:53 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.perex.cz B736211E2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=perex.cz; s=default; t=1683028553; bh=1mI958yPPhDPPcJ7Z4ZWt8wLKReatfW0myv8PEBJZ3A=; h=From:To:Cc:Subject:Date:From; b=RnMODiVHF5fGLC1etMj2lb3VCn0ie/SvbeVh26BR2NsLFRTVDeLg80Mcb7pmm5hUh s3tq1/EphLb+A0zWhm+jfcw0QW4BPfw+8gPNR8WQ8qaboRWcy/P2XOPYXiabUwhmHU 3OX+ISXRsQY2oyhojHvOify6vx1jALQcPYN1jDso= Received: from p1gen2.perex-int.cz (unknown [192.168.100.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: perex) by mail1.perex.cz (Perex's E-mail Delivery System) with ESMTPSA; Tue, 2 May 2023 13:55:50 +0200 (CEST) From: Jaroslav Kysela To: ALSA development Subject: [PATCH] ALSA: uapi: pcm: control the filling of the silence samples for drain Date: Tue, 2 May 2023 13:55:36 +0200 Message-Id: <20230502115536.986900-1-perex@perex.cz> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Message-ID-Hash: M5VQGOENXQN5HRKOJGOTOFLJ6TSBXPV2 X-Message-ID-Hash: M5VQGOENXQN5HRKOJGOTOFLJ6TSBXPV2 X-MailFrom: perex@perex.cz X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Takashi Iwai X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Introduce SNDRV_PCM_INFO_PERFECT_DRAIN and SNDRV_PCM_HW_PARAMS_NO_DRAIN_SILENCE flags to fully control the filling of the silence samples in the drain ioctl. Actually, the configurable silencing is going to be implemented in the user space [1], but drivers (hardware) may not require this operation. Those flags do the bidirectional setup for this operation: 1) driver may notify the presence of the perfect drain 2) user space may not require the filling of the silence samples to inhibit clicks If we decide to move this operation to the kernel space in future, the SNDRV_PCM_INFO_PERFECT_DRAIN flag may handle this situation without double "silence" processing (user + kernel space). The ALSA API should be universal, so forcing the behaviour (modifying of the ring buffer with any samples) for the drain operation is not ideal. [1] https://lore.kernel.org/alsa-devel/20230502115010.986325-1-perex@perex.cz/ Signed-off-by: Jaroslav Kysela --- include/uapi/sound/asound.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index 0aa955aa8246..e4b0f95694c5 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -274,6 +274,7 @@ typedef int __bitwise snd_pcm_subformat_t; #define SNDRV_PCM_INFO_DOUBLE 0x00000004 /* Double buffering needed for PCM start/stop */ #define SNDRV_PCM_INFO_BATCH 0x00000010 /* double buffering */ #define SNDRV_PCM_INFO_SYNC_APPLPTR 0x00000020 /* need the explicit sync of appl_ptr update */ +#define SNDRV_PCM_INFO_PERFECT_DRAIN 0x00000040 /* silencing at the end of stream is not required */ #define SNDRV_PCM_INFO_INTERLEAVED 0x00000100 /* channels are interleaved */ #define SNDRV_PCM_INFO_NONINTERLEAVED 0x00000200 /* channels are not interleaved */ #define SNDRV_PCM_INFO_COMPLEX 0x00000400 /* complex frame organization (mmap only) */ @@ -383,6 +384,9 @@ typedef int snd_pcm_hw_param_t; #define SNDRV_PCM_HW_PARAMS_NORESAMPLE (1<<0) /* avoid rate resampling */ #define SNDRV_PCM_HW_PARAMS_EXPORT_BUFFER (1<<1) /* export buffer */ #define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2) /* disable period wakeups */ +#define SNDRV_PCM_HW_PARAMS_NO_DRAIN_SILENCE (1<<3) /* supress drain with the filling + * of the silence samples + */ struct snd_interval { unsigned int min, max;