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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F03C2C433E0 for ; Tue, 16 Jun 2020 13:36:22 +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 7DD6120C56 for ; Tue, 16 Jun 2020 13:36:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="OoJcdZMx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DD6120C56 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 00F54166C; Tue, 16 Jun 2020 15:35:30 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 00F54166C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1592314581; bh=lX7Kw3bq0zltP0rnDaFpBt1BLkCvVk9uVPlRjNSDKCY=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=OoJcdZMx1T2A9Z9h7mOH8E/m+RbGVqMO/Uwl2h8SZAcAfTvi4SPFEKcAhYs+WECsY PrBCwMCnQ7BtXSOk23mJdlTlrrPLUJ2BHtmoFd5Ygiod/mqTbIK8Bi740I768T/nwl XSE2DPJeaWk63y+KBklMuTCd3c/W5VdolITLhLAE= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 5C20CF80217; Tue, 16 Jun 2020 15:35:30 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id E6E77F8022B; Tue, 16 Jun 2020 15:35:28 +0200 (CEST) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 0EC21F800EF for ; Tue, 16 Jun 2020 15:35:25 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 0EC21F800EF X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 6CB08AE00; Tue, 16 Jun 2020 13:35:28 +0000 (UTC) Date: Tue, 16 Jun 2020 15:35:23 +0200 Message-ID: From: Takashi Iwai To: Mark Hills Subject: Re: [PATCH 3/3] echoaudio: Address bugs in the interrupt handling In-Reply-To: <20200616131743.4793-3-mark@xwax.org> References: <2006161409060.30751@stax.localdomain> <20200616131743.4793-3-mark@xwax.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: 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 15:17:43 +0200, Mark Hills wrote: > > +/* Update software pointer to match the hardware > + * > + * Return: 1 if we crossed a period threshold, otherwise 0 > + */ > +static int snd_echo_poll_substream(struct snd_pcm_substream *substream) This is a bit confusing name. One would imagine from the function name as if it were about the handling of poll() syscall. > +{ > + struct snd_pcm_runtime *runtime = substream->runtime; > + struct audiopipe *pipe = runtime->private_data; > + unsigned counter, step, period, last_period; > + size_t buffer_bytes; > + > + if (pipe->state != PIPE_STATE_STARTED) > + return 0; > + > + counter = le32_to_cpu(*pipe->dma_counter); > + > + period = bytes_to_frames(runtime, counter) > + / runtime->period_size; > + last_period = bytes_to_frames(runtime, pipe->last_counter) > + / runtime->period_size; > + > + if (period == last_period) > + return 0; /* don't do any work yet */ > + > + step = counter - pipe->last_counter; > + pipe->last_counter = counter; Dose this calculation consider the overlap of 32bit integer of the counter? (I'm not sure whether the old code did it right, though.) thanks, Takashi