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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0496BC433E1 for ; Tue, 16 Jun 2020 19:47:10 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 538C5214D8 for ; Tue, 16 Jun 2020 19:47:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="mO6P7384" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 538C5214D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shiny.it Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id E3A1F165E; Tue, 16 Jun 2020 21:46:17 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz E3A1F165E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1592336828; bh=pMqjLlVOizE0h5zjPZ/YAZqRz30NRq+JGtfVzkto9r8=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=mO6P7384ur401CU5+cbK2jbBnUbF3JosSJS6KITOodS4AkgnvHfGQTvhu75eevyBR rHPr29zNgUqWRu4m6z9c8YpXhfibCN952W8NobJOhAKsKrSToDXDsnIojp4ksg0KC1 JOrQvPWz5L2UnlP/83SH3dyyV6AsvXxdwqjSwC/Y= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 7AAB4F80217; Tue, 16 Jun 2020 21:46:17 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 02086F8022B; Tue, 16 Jun 2020 21:46:16 +0200 (CEST) Received: from denise.shiny.it (denise.shiny.it [185.206.84.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 18B7DF80101 for ; Tue, 16 Jun 2020 21:46:09 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 18B7DF80101 Received: from wc1 (localhost [127.0.0.1]) by denise.shiny.it (8.15.2/8.15.2) with ESMTP id 05GJk4k8024115; Tue, 16 Jun 2020 21:46:05 +0200 Date: Tue, 16 Jun 2020 21:46:10 +0200 From: Giuliano Pochini To: Mark Hills Subject: Re: [PATCH 3/3] echoaudio: Address bugs in the interrupt handling Message-ID: <20200616214603.71cfe49b@wc1> In-Reply-To: <20200616131743.4793-3-mark@xwax.org> References: <2006161409060.30751@stax.localdomain> <20200616131743.4793-3-mark@xwax.org> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Takashi Iwai , alsa-devel@alsa-project.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Tue, 16 Jun 2020 14:17:43 +0100 Mark Hills wrote: > Distorted audio appears occasionally, affecting either playback > or capture and requiring the affected substream to be closed by > all applications and re-opened. Yes, it also happens here very rarely (one time every some months) and I failed to reproduce the problem. > The best way I have found to reproduce the bug is to use dmix in > combination with Chromium, which opens the audio device multiple > times in threads. Anecdotally, the problems appear to have increased > with faster CPUs. > > Since applying this patch I have not had problems, where previously > they would occur several times a day. > > This patch addresses the following issues: > > * Check for progress using the counter from the hardware, not after > it has been truncated to the buffer. > > There appears to be a possible bug if a whole ringbuffer advances > between interrupts, it goes unnoticed. In that case the stream must be restarted anyway due to xrun. > * Remove chip->last_period: > > It's trivial to derive from pipe->last_counter, and inside pipe > is where it more logically belongs. This has less scope for bugs > as it is not wrapped to the buffer length. Ok. > * Remove the accessing of pipe->dma_counter twice in the interrupt > handler: Why twice? > +static int snd_echo_poll_substream(struct snd_pcm_substream *substream) > [...] > static irqreturn_t snd_echo_interrupt(int irq, void *dev_id) > [...] Looks fine to me. -- Giuliano.