From nobody Tue Feb 10 20:08:38 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=ilande.co.uk Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1694253035014391.5927386677449; Sat, 9 Sep 2023 02:50:35 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qeuaW-0005ko-EA; Sat, 09 Sep 2023 05:49:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qeuaV-0005kK-Fg for qemu-devel@nongnu.org; Sat, 09 Sep 2023 05:49:11 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qeuaT-0005Iv-C7 for qemu-devel@nongnu.org; Sat, 09 Sep 2023 05:49:11 -0400 Received: from [2a00:23c4:8baf:5f00:e007:7058:31bc:5be9] (helo=localhost.localdomain) by mail.ilande.co.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qeuaN-0000uO-88; Sat, 09 Sep 2023 10:49:07 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=ilande.co.uk; s=20220518; h=Subject:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:To:From:Sender:Reply-To:Cc: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=AA8s1jLClq+X8IUUxLYTPVljty8wsZNJ4UerQIUqDwI=; b=OZ2OXTEiG47k348JDgLeVU9m7I KBQkqiQCrWhALHCzkz1x2IZ48rJgE/3OsDJU43hwwuUSnZj3vHJI5a+xEvQqEkR/4G/TFdFdp6iHg tjCQC5PaRtggu1mLQboFxoVT2GY7L5BKGKIG2Okua9QaAhoDuQwCKjQzUhxTXn0Tf0LStwd3ZZC9g nGrnGns+FcYSYwOXSrmWeFmXjtvdzpAdhqGwNOlK+MRykKTYBL0BNdxo5MtXytE1cgr8zKjgbL1NU j+5Nzr1/xIoIHvbRzlVz8JUxLnRPnFLr0EevUtcOvYuE4PSs9uYa2Ht6cVFlQj3VqkEq5I7h/nGDe ZspIIgkIUai/YSYe6c2cWOUPo7azOCUMpuCfc90VzpR2KgzAdMnJsWuEZ5rbOnBIVYWpSI4vbAkrd bFwtomYnQnfMZN4tmWhaQCCPE7PqZPyaJ5y8/M8Xmvg7cdJvuc25WgwwLfZpxPjb1484mkvo/iRuy gyoE89Aqv+k4za4m4lH3Jhbg2Q5UN9ixA3RJXbEbLDhRGSZp3p127MZaFUH2YoYTSxSKa06xsfmEQ 8cPogrQQ/0lAIXrgfLKrgyCoQbtaB7Z0nDHuVB+yjbCMe+onPVBidyOHkg/j3Ljl0Qgoem0ropSxF bZELfa643NgUmlezXpAsZUsi0TIUEt+7spumNJjWc=; From: Mark Cave-Ayland To: laurent@vivier.eu, qemu-devel@nongnu.org Date: Sat, 9 Sep 2023 10:48:15 +0100 Message-Id: <20230909094827.33871-9-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230909094827.33871-1-mark.cave-ayland@ilande.co.uk> References: <20230909094827.33871-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a00:23c4:8baf:5f00:e007:7058:31bc:5be9 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH v2 08/20] asc: generate silence if FIFO empty but engine still running X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.ilande.co.uk) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.ilande.co.uk 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1694253036161100001 Content-Type: text/plain; charset="utf-8" MacOS (un)helpfully leaves the FIFO engine running even when all the sample= s have been written to the hardware, and expects the FIFO status flags and IRQ to = be updated continuously. There is an additional problem in that not all audio backends guarantee an all-zero output when there is no FIFO data available, in particular the Win= dows dsound backend which re-uses its internal circular buffer causing the last = played sound to loop indefinitely. Whilst this is effectively a bug in the Windows dsound backend, work around= it for now using a simple heuristic: if the FIFO remains empty for half a cycle (~23ms) then continuously fill the generated buffer with empty silence. Signed-off-by: Mark Cave-Ayland Reviewed-by: Laurent Vivier --- hw/audio/asc.c | 19 +++++++++++++++++++ include/hw/audio/asc.h | 2 ++ 2 files changed, 21 insertions(+) diff --git a/hw/audio/asc.c b/hw/audio/asc.c index 336ace0cd6..b01b285512 100644 --- a/hw/audio/asc.c +++ b/hw/audio/asc.c @@ -334,6 +334,21 @@ static void asc_out_cb(void *opaque, int free_b) } =20 if (!generated) { + /* Workaround for audio underflow bug on Windows dsound backend */ + int64_t now =3D qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + int silent_samples =3D muldiv64(now - s->fifo_empty_ns, + NANOSECONDS_PER_SECOND, ASC_FREQ); + + if (silent_samples > ASC_FIFO_CYCLE_TIME / 2) { + /* + * No new FIFO data within half a cycle time (~23ms) so fill t= he + * entire available buffer with silence. This prevents an issue + * with the Windows dsound backend whereby the sound appears to + * loop because the FIFO has run out of data, and the driver + * reuses the stale content in its circular audio buffer. + */ + AUD_write(s->voice, s->silentbuf, samples << s->shift); + } return; } =20 @@ -611,6 +626,7 @@ static void asc_unrealize(DeviceState *dev) ASCState *s =3D ASC(dev); =20 g_free(s->mixbuf); + g_free(s->silentbuf); =20 AUD_remove_card(&s->card); } @@ -633,6 +649,9 @@ static void asc_realize(DeviceState *dev, Error **errp) s->samples =3D AUD_get_buffer_size_out(s->voice) >> s->shift; s->mixbuf =3D g_malloc0(s->samples << s->shift); =20 + s->silentbuf =3D g_malloc0(s->samples << s->shift); + memset(s->silentbuf, 0x80, s->samples << s->shift); + /* Add easc registers if required */ if (s->type =3D=3D ASC_TYPE_EASC) { memory_region_add_subregion(&s->asc, ASC_EXTREG_OFFSET, diff --git a/include/hw/audio/asc.h b/include/hw/audio/asc.h index d9412815c3..4741f92c46 100644 --- a/include/hw/audio/asc.h +++ b/include/hw/audio/asc.h @@ -68,6 +68,8 @@ struct ASCState { int samples; int shift; =20 + uint8_t *silentbuf; + /* Time when we were last able to generate samples */ int64_t fifo_empty_ns; =20 --=20 2.39.2