Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750831AbWAJJnr (ORCPT ); Tue, 10 Jan 2006 04:43:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750768AbWAJJnr (ORCPT ); Tue, 10 Jan 2006 04:43:47 -0500 Received: from gate.perex.cz ([85.132.177.35]:51347 "EHLO gate.perex.cz") by vger.kernel.org with ESMTP id S1750753AbWAJJnq (ORCPT ); Tue, 10 Jan 2006 04:43:46 -0500 Date: Tue, 10 Jan 2006 10:43:44 +0100 (CET) From: Jaroslav Kysela X-X-Sender: perex@tm8103.perex-int.cz To: Hannu Savolainen Cc: Lee Revell , Takashi Iwai , linux-sound@vger.kernel.org, LKML Subject: Re: [OT] ALSA userspace API complexity In-Reply-To: Message-ID: References: <20050726150837.GT3160@stusta.de> <20060103193736.GG3831@stusta.de> <20060104030034.6b780485.zaitcev@redhat.com> <1136504460.847.91.camel@mindpipe> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 34 On Fri, 6 Jan 2006, Hannu Savolainen wrote: > On Thu, 5 Jan 2006, Lee Revell wrote: > > > On Fri, 2006-01-06 at 01:06 +0200, Hannu Savolainen wrote: > > > We have not received any single bug report that is caused > > > by the concept of kernel mixing. > > > Kernel mixing is not rocket science. All you need to do is picking a > > > sample from the output buffers of each of the applications, sum them > > > together (with some volume scaling) and feed the result to the > > > physical > > > device. > > > > Hey, interesting, this is exactly what dmix does in userspace. And we > > have not seen any bug reports caused by the concept of userspace mixing > > (just implementation bugs like any piece of software). > Having dmix working in user space doesn't prove that kernel level mixing > is evil. This was the original topic. Overloading interrupt handlers with extra things is evil (and I bet you're mixing samples in the interrupt handler). Even the network stack uses interrupts only for DMA management and not for any extra operations. Jaroslav ----- Jaroslav Kysela Linux Kernel Sound Maintainer ALSA Project, SUSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/