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 0656AC433EF for ; Mon, 6 Dec 2021 15:25:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230354AbhLFP3J (ORCPT ); Mon, 6 Dec 2021 10:29:09 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:41576 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385534AbhLFPZX (ORCPT ); Mon, 6 Dec 2021 10:25:23 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 922CA612D3; Mon, 6 Dec 2021 15:21:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78498C341C6; Mon, 6 Dec 2021 15:21:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638804114; bh=BlMii64HDJCaC92Mm5g1HBrpyBkQPk6BAJyffq0fCVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wl4pqy3m+30G8/VurFLw+4LWGV/YbEeZRUZmFbqn6krUmOgvJfzwHxZgAZ9+iJ0LW stamFfzvFkcc8aEMgD8FXMLac3gIeCFa5OSDXQuDTBh6d4awzA2org+7PE1JuBFDAe gVgN5w1wl+T0iT3sxoiJPxrc+URsIWsEf2j+bM2E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai Subject: [PATCH 5.15 004/207] ALSA: usb-audio: Disable low-latency mode for implicit feedback sync Date: Mon, 6 Dec 2021 15:54:18 +0100 Message-Id: <20211206145610.335267634@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211206145610.172203682@linuxfoundation.org> References: <20211206145610.172203682@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit bceee75387554f682638e719d1ea60125ea78cea upstream. When a playback stream runs in the implicit feedback mode, its operation is passive and won't start unless the capture packet is received. This behavior contradicts with the low-latency playback mode, and we should turn off lowlatency_playback flag accordingly. In theory, we may take the low-latency mode when the playback-first quirk is set, but it still conflicts with the later operation with the fixed packet numbers, so it's disabled all together for now. Link: https://lore.kernel.org/r/20210929080844.11583-6-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/pcm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -595,6 +595,9 @@ static int lowlatency_playback_available /* free-wheeling mode? (e.g. dmix) */ if (runtime->stop_threshold > runtime->buffer_size) return false; + /* implicit feedback mode has own operation mode */ + if (snd_usb_endpoint_implicit_feedback_sink(subs->data_endpoint)) + return false; /* too short periods? */ if (subs->data_endpoint->nominal_queue_size >= subs->buffer_bytes) return false;