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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 234F0C433FE for ; Thu, 13 Oct 2022 07:30:25 +0000 (UTC) Received: from localhost ([::1]:37702 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oisff-0002Az-Ux for qemu-devel@archiver.kernel.org; Thu, 13 Oct 2022 03:30:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34450) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ois5C-0005J7-UF for qemu-devel@nongnu.org; Thu, 13 Oct 2022 02:52:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39423) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ois5B-0006nH-8p for qemu-devel@nongnu.org; Thu, 13 Oct 2022 02:52:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665643960; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=22pBYRTIMvEPA0Y2kGJFhykaWUMI7kqIIgn167stpvc=; b=BS5JyL3r1BhSeBTWip6y6mWyCNlVAJ238qhHnZGMm1QMJZN+mmszuwIjaycr1XNxI5khuX OhLbVqd6kBLDNyMojkvYv4iytjijIzolIHGx2KPhPal4kamspEQ8PKXrZzDzA1St6E3quN 7ebWvCPwBgnQ9EqX/atzZJinsNKGLAY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-498-AsYnbbXWPB2xkgMuqHcWcg-1; Thu, 13 Oct 2022 02:52:37 -0400 X-MC-Unique: AsYnbbXWPB2xkgMuqHcWcg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D501F3806703; Thu, 13 Oct 2022 06:52:36 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.195.183]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 74B742166BA3; Thu, 13 Oct 2022 06:52:36 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 81AF5180062C; Thu, 13 Oct 2022 08:52:24 +0200 (CEST) From: Gerd Hoffmann To: qemu-devel@nongnu.org Cc: David Hildenbrand , Gerd Hoffmann , Kashyap Chamarthy , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Markus Armbruster , Eric Auger , Christian Schoenebeck , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Marcel Apfelbaum , "Michael S. Tsirkin" , Eric Blake , =?UTF-8?q?Volker=20R=C3=BCmelin?= Subject: [PULL 04/26] alsaaudio: reduce playback latency Date: Thu, 13 Oct 2022 08:52:02 +0200 Message-Id: <20221013065224.1864145-5-kraxel@redhat.com> In-Reply-To: <20221013065224.1864145-1-kraxel@redhat.com> References: <20221013065224.1864145-1-kraxel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Volker Rümelin Change the buffer_get_free pcm_ops function to report the free ALSA playback buffer. The generic buffer becomes a temporary buffer and is empty after a call to audio_run_out(). Signed-off-by: Volker Rümelin Acked-by: Marc-André Lureau Message-Id: <20220923183640.8314-4-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann --- audio/alsaaudio.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/audio/alsaaudio.c b/audio/alsaaudio.c index 4a61378cd757..7a2a94cd427d 100644 --- a/audio/alsaaudio.c +++ b/audio/alsaaudio.c @@ -602,6 +602,42 @@ static int alsa_open(bool in, struct alsa_params_req *req, return -1; } +static size_t alsa_buffer_get_free(HWVoiceOut *hw) +{ + ALSAVoiceOut *alsa = (ALSAVoiceOut *)hw; + snd_pcm_sframes_t avail; + size_t alsa_free, generic_free, generic_in_use; + + avail = snd_pcm_avail_update(alsa->handle); + if (avail < 0) { + if (avail == -EPIPE) { + if (!alsa_recover(alsa->handle)) { + avail = snd_pcm_avail_update(alsa->handle); + } + } + if (avail < 0) { + alsa_logerr(avail, + "Could not obtain number of available frames\n"); + avail = 0; + } + } + + alsa_free = avail * hw->info.bytes_per_frame; + generic_free = audio_generic_buffer_get_free(hw); + generic_in_use = hw->samples * hw->info.bytes_per_frame - generic_free; + if (generic_in_use) { + /* + * This code can only be reached in the unlikely case that + * snd_pcm_avail_update() returned a larger number of frames + * than snd_pcm_writei() could write. Make sure that all + * remaining bytes in the generic buffer can be written. + */ + alsa_free = alsa_free > generic_in_use ? alsa_free - generic_in_use : 0; + } + + return alsa_free; +} + static size_t alsa_write(HWVoiceOut *hw, void *buf, size_t len) { ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw; @@ -916,7 +952,7 @@ static struct audio_pcm_ops alsa_pcm_ops = { .init_out = alsa_init_out, .fini_out = alsa_fini_out, .write = alsa_write, - .buffer_get_free = audio_generic_buffer_get_free, + .buffer_get_free = alsa_buffer_get_free, .run_buffer_out = audio_generic_run_buffer_out, .enable_out = alsa_enable_out, -- 2.37.3