Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756602Ab2BHIao (ORCPT ); Wed, 8 Feb 2012 03:30:44 -0500 Received: from cantor2.suse.de ([195.135.220.15]:35194 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756511Ab2BHIan (ORCPT ); Wed, 8 Feb 2012 03:30:43 -0500 Date: Wed, 08 Feb 2012 09:30:40 +0100 Message-ID: From: Takashi Iwai To: "Heasley, Seth" Cc: David Henningsson , "alsa-devel@alsa-project.org" , "perex@perex.cz" , "Ralston, James D" , "linux-kernel@vger.kernel.org" Subject: Re: [alsa-devel] [PATCH 1/6] hda_intel: Add Lynx Point HD Audio Controller DeviceIDs In-Reply-To: References: <201201231624.31275.seth.heasley@intel.com> <4F1E7DC0.5060208@canonical.com> <4F30ADB6.1000109@canonical.com> User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.3 (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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1529 Lines: 36 At Wed, 8 Feb 2012 00:35:33 +0000, Heasley, Seth wrote: > > >> I'm also in favor of not rocking the boat, but I'm curious what > >changing this would entail, and what would be the advantage or rationale > >for making the change? > > > >Reading the LPIB register, and reading the DMA position buffer, are two > >different methods of reading the current playback (or recording) > >position, i e which sample is currently being played back. > > > >The problem is that some chipsets prefer one method over the other, i e, > >only one of the methods work reliably. And if the other method only > >breaks occasionally, this can be quite difficult to detect and track > >down - we will have users complaining about their audio sometimes either > >sounding distorted, maybe not working at all, or just once in a while > >glitches. All of these symptoms can have many causes, so deducing that > >to a broken playback position is time consuming. That's why I think it's > >worth the extra question, to get it right from the start. > > > >So...thanks in advance for looking it up for us? :-) > > I'm inquiring about it, but I can say that it seems to work just fine using the DMA position buffer. OK, I merged the patch now as is. Please let me know if you find a problem. thanks, Takashi -- 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/