From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sriram Periyasamy Subject: Re: [PATCH] ASoC: Intel: Power down links before turning off display audio power Date: Mon, 25 Jun 2018 14:23:49 +0530 Message-ID: <20180625085348.GA30506@intel.com> References: <1529659551-22902-1-git-send-email-sriramx.periyasamy@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by alsa0.perex.cz (Postfix) with ESMTP id 368862675C8 for ; Mon, 25 Jun 2018 11:05:30 +0200 (CEST) Content-Disposition: inline In-Reply-To: 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: Takashi Iwai Cc: ALSA ML , Patches Audio , Pierre-Louis Bossart , Liam Girdwood , Mark Brown , Sanyog Kale List-Id: alsa-devel@alsa-project.org On Fri, Jun 22, 2018 at 07:14:50PM +0200, Takashi Iwai wrote: > On Fri, 22 Jun 2018 18:42:24 +0200, > Pierre-Louis Bossart wrote: > > > > On 6/22/18 4:25 AM, Sriram Periyasamy wrote: > > > On certain platforms, Display HDMI HDA codec was not going to sleep state > > > after the use when links are powered down after turning off the display > > > power. As per the HW recommendation, links are powered down before turning > > > off the display power to ensure that the codec goes to sleep state. > > > > The change looks ok, I am still not clear on display power > > management. snd_hdac_display_power is called both from hdac_hdmi.c and > > skl.c in the respective probe/suspend/resume routines, wondering if > > this is redundant or intentional. > > Yeah, it looks like that skl.c keeps the display power on by assuming > that it's turned off by the codec driver, but it doesn't happen > actually. I also find it fishy there... > snd_hdac_display_power is called intentionally to ensure that the codec is powered up before any communication is initiated from either skl.c or hdac_hdmi.c. Thanks, Sriram.