From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larry Finger Subject: Re: 64-bit DMA problems with BCM4312 using b43 Date: Fri, 13 Nov 2009 21:40:53 -0600 Message-ID: <4AFE26C5.5080402@lwfinger.net> References: <4AFD958E.1000303@lwfinger.net> <20091113201112.GA5540@srcf.ucam.org> <200911132144.24110.mb@bu3sch.de> <4AFDCA0E.4080007@lwfinger.net> <20091113211306.GA6600@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-yw0-f202.google.com ([209.85.211.202]:59899 "EHLO mail-yw0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755465AbZKNDku (ORCPT ); Fri, 13 Nov 2009 22:40:50 -0500 In-Reply-To: <20091113211306.GA6600@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: Michael Buesch , bcm43xx-dev@lists.berlios.de, Linux ACPI , LKML On 11/13/2009 03:13 PM, Matthew Garrett wrote: > On Fri, Nov 13, 2009 at 03:05:18PM -0600, Larry Finger wrote: > >> I'm in the process of creating a patch to set the latency to 200 usec. The >> default is 2000. On my fast prosessors, it should not be anything nearly that >> slow. If we determine this to be the problem, then we can try tuning. > > The latency is the amount of time it takes to get out of deep C states > and into C0. That's a function of the processor design rather than the > frequency. Thanks for your suggestion. The value of 200 fixed one of the two machines and greatly improved the other. He is currently testing with a value of 150, and will try 100 if that still fails. Larry