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 1DDB0C77B61 for ; Mon, 1 May 2023 07:22:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232220AbjEAHWi (ORCPT ); Mon, 1 May 2023 03:22:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229556AbjEAHWf (ORCPT ); Mon, 1 May 2023 03:22:35 -0400 X-Greylist: delayed 308 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 01 May 2023 00:22:33 PDT Received: from bluemchen.kde.org (bluemchen.kde.org [IPv6:2001:470:142:8::100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D1A3B6 for ; Mon, 1 May 2023 00:22:33 -0700 (PDT) Received: from ugly.fritz.box (localhost [127.0.0.1]) by bluemchen.kde.org (Postfix) with ESMTP id 5F62024179; Mon, 1 May 2023 03:17:20 -0400 (EDT) Received: by ugly.fritz.box (masqmail 0.3.4, from userid 1000) id 1ptNmi-FyQ-00; Mon, 01 May 2023 09:17:20 +0200 Date: Mon, 1 May 2023 09:17:20 +0200 From: Oswald Buddenhagen To: Jeff Chua Cc: lkml , Bagas Sanjaya , Takashi Iwai Subject: Re: linux-6.4 alsa sound broken Message-ID: Mail-Followup-To: Oswald Buddenhagen , Jeff Chua , lkml , Bagas Sanjaya , Takashi Iwai References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 01, 2023 at 11:59:12AM +0800, Jeff Chua wrote: >Latest git pull from Linus's tree ... playing a simple sound file will >resulted in a lot of echo. > how _exactly_ does it sound? have you recorded a file through loopback for us to investigate? best would be a short sample of a clean wave (sine or sawtooth) with some leading and trailing silence. >Running on Lenovo X1 with .. >00:1f.3 Audio device: Intel Corporation Alder Lake PCH-P High >Definition Audio Controller (rev 01) > >I've bisected and reverted the following patch fixed the problem. > this seems weird. so my first thought is: are you _sure_ that your bisect isn't "contaminated" somehow? is the effect consistent across several reboots with the same build? does re-applying my patch immediately re-introduce the problem? - this code is about silencing. getting dropouts or no playback at all would be plausible, while echo (that is, repetition) seems surprising. theoretically, the driver may be setting a bad fill_silence() callback which copies some garbage instead of zeroing, but the HDA driver doesn't set one at all (i.e., uses the default one). - this code must be explicitly enabled, which for all i know is done by almost nothing. what players did you try? did you get consistent results? did you try taking out audio servers from the equation? - the affected hardware belongs to the extremely widely used HDA family, which at the layer the patch is even remotely connected with is completely standardized. so _a lot_ of people should be affected, and we should be getting reports like yours by the dozen. are we? of course i can't exclude the possibility that my patch is affected by an uninitialized variable or memory corruption (or in the worst case causes it), which would of course have very hard to predict effects. but that should be investigated properly instead of just reverting, lest we might be papering over a much more serious problem. -- ossi >commit 9f656705c5faa18afb26d922cfc64f9fd103c38d >Author: Oswald Buddenhagen >Date: Thu Apr 20 13:33:23 2023 +0200 > > ALSA: pcm: rewrite snd_pcm_playback_silence() > > The auto-silencer supports two modes: "thresholded" to fill up "just > enough", and "top-up" to fill up "as much as possible". The two modes > used rather distinct code paths, which this patch unifies. The only > remaining distinction is how much we actually want to fill. > > This fixes a bug in thresholded mode, where we failed to use new_hw_ptr, > resulting in under-fill. > > Top-up mode is now more well-behaved and much easier to understand in > corner cases. > > This also updates comments in the proximity of silencing-related data > structures. > > Signed-off-by: Oswald Buddenhagen > Reviewed-by: Jaroslav Kysela > Link: https://lore.kernel.org/r/20230420113324.877164-1-oswald.buddenhagen@gmx.de > Signed-off-by: Takashi Iwai