From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bard Liao Subject: Re: [PATCH] ASoC: rt5677: Reconfigure PLL1 after resume Date: Thu, 17 Dec 2015 05:21:05 +0000 Message-ID: References: <1450216285-14875-1-git-send-email-benzh@chromium.org> <20151216192127.GQ5727@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from rtits2.realtek.com.tw (rtits2.realtek.com [60.250.210.242]) by alsa0.perex.cz (Postfix) with ESMTP id 8FD752654B7 for ; Thu, 17 Dec 2015 06:21:12 +0100 (CET) In-Reply-To: <20151216192127.GQ5727@sirena.org.uk> Content-Language: zh-TW 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: Mark Brown , Ben Zhang Cc: Oder Chiou , "alsa-devel@alsa-project.org" , Liam Girdwood , John Lin , Anatol Pomozov , Dylan Reid List-Id: alsa-devel@alsa-project.org > -----Original Message----- > From: Mark Brown [mailto:broonie@kernel.org] > Sent: Thursday, December 17, 2015 3:21 AM > To: Ben Zhang > Cc: alsa-devel@alsa-project.org; Liam Girdwood; Bard Liao; Oder Chiou; > John Lin; Dylan Reid; Anatol Pomozov > Subject: Re: [PATCH] ASoC: rt5677: Reconfigure PLL1 after resume > > On Tue, Dec 15, 2015 at 01:51:25PM -0800, Ben Zhang wrote: > > Sometimes PLL1 stops working if the codec loses power during suspend > > (when pow-ldo2 or reset gpio is used). > > MX-7Bh(RT5677_PLL1_CTRL2) is cleared and won't be restored by > regcache > > since it's volatile. MX-7Bh has one status bit and M code for PLL1. > > rt5677_set_dai_pll doesn't reconfigure > > PLL1 after resume because it thinks the PLL params are not changed. > > > This patch clears the cached PLL params at resume so that > > rt5677_set_dai_pll can reconfigure the PLL after resume. > > This is something I'd expect the machine driver to handle - if it's stopped > using the PLL I'd expect it to explicitly turn it off, suspend (or the CODEC > going idle for that matter normally, the PLL is burning > power) should do that. If anything I'd expect the CODEC driver to restore > the current settings. The main reason of this patch is MX-7Bh(RT5677_PLL1_CTRL2) is volatile. However, the status bit of MX-7Bh is currently not used by codec driver. So, it should be no problem if we set it non-volatile. > > That said I'll apply this since it at least doesn't make things worse. Can we revert it and resend a patch? > > ------Please consider the environment before printing this e-mail.