From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: wm8960 sleep time is too long when system suspend Date: Mon, 2 Nov 2015 09:18:55 +0000 Message-ID: <20151102091855.GO10520@ck-lbox> References: <20151102084402.GA7603@shlinux2> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx0b-001ae601.pphosted.com (mx0b-001ae601.pphosted.com [67.231.152.168]) by alsa0.perex.cz (Postfix) with ESMTP id A89B4260691 for ; Mon, 2 Nov 2015 10:34:24 +0100 (CET) Content-Disposition: inline In-Reply-To: <20151102084402.GA7603@shlinux2> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Zidan Wang Cc: alsa-devel@alsa-project.org, broonie@kernel.org, patches@opensource.wolfsonmicro.com List-Id: alsa-devel@alsa-project.org On Mon, Nov 02, 2015 at 04:44:04PM +0800, Zidan Wang wrote: > Hi Mark, > > In wm8960 codec driver, suspend_bias_off has been enabled. So when system suspend, the wm8960 codec will go to bias off, > it will disable VMID and VREF, then sleep 600ms. It seems that 600ms is too long for system suspend. > > Because the wm8960 datasheet don't mentioned the sleep time, so i want to check with you if we can shorten the sleep time. I can't say that I am explicit familiar with the required delay there, but the comment in the code says that we are letting VMID and VREF discharge, which I certainly could believe would take a while. My guess would be that we likely weren't super excited about putting a 600mS delay in, which probably means it was necessary for some reason. How much where you hoping to reduce it by? I can see if I can find a hardware engineer who still remembers enough about the part to discuss it with. Thanks, Charles