From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: Re: [PATCH v3] ASoC: fsl: imx-wm8962: Grant hw_params/free() permission to control FLL Date: Wed, 18 Dec 2013 13:13:36 +0800 Message-ID: <20131218051334.GA7648@MrMyself> References: <1386842368-19951-1-git-send-email-Guangyu.Chen@freescale.com> <20131217225002.GR28455@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from va3outboundpool.messaging.microsoft.com (va3ehsobe006.messaging.microsoft.com [216.32.180.16]) by alsa0.perex.cz (Postfix) with ESMTP id 07BE62610B9 for ; Wed, 18 Dec 2013 06:34:31 +0100 (CET) Content-Disposition: inline In-Reply-To: <20131217225002.GR28455@sirena.org.uk> 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 Cc: tiwai@suse.de, linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, lgirdwood@gmail.com List-Id: alsa-devel@alsa-project.org On Tue, Dec 17, 2013 at 10:50:02PM +0000, Mark Brown wrote: > On Thu, Dec 12, 2013 at 05:59:28PM +0800, Nicolin Chen wrote: > > > + mask = WM8962_MIXINL_TO_HPMIXL_MASK | WM8962_MIXINR_TO_HPMIXL_MASK | > > + WM8962_IN4L_TO_HPMIXL_MASK | WM8962_IN4R_TO_HPMIXL_MASK; > > + bypass |= snd_soc_read(codec, WM8962_HEADPHONE_MIXER_1) & mask; > > + bypass |= snd_soc_read(codec, WM8962_HEADPHONE_MIXER_2) & mask; > > + bypass |= snd_soc_read(codec, WM8962_SPEAKER_MIXER_1) & mask; > > + bypass |= snd_soc_read(codec, WM8962_SPEAKER_MIXER_2) & mask; > > + > > + /* Don't diable FLL if running multi-substreams or analogue bypass */ > > + if (codec_dai->active != 1 || bypass) > > + return 0; > > I don't think this works with the power down delay we do on playback - > the DAI will go inactive when closed but we'll still have the CODEC > active and using its clocks until the power down time has elapsed if > it's a playback DAI. Trying to reclock the device while active is at > best risky, even if it's muted. > > I do think refcounting from both here and the bias level changes is > going to be the most robust thing, that'd also avoid the need to peer > into the CODEC register map. I've tried count reference way to handle FLL enabler/disabler here before I sent this version. But the result shows the FLL would be never disabled in hw_free() because the refcount is accumulated to 2, one from hw_params() and the other from set_bias_level(PREPARE), which just made this patch meaningless to me. So the reclocking with bypass checking seems to be the last resort I can figure out right here as the playback flow for 'aplay -Dhw:0 44k16bit.wav 48k24bit.wav' does need to reprogram the FLL during CODEC active. Thank you, Nicolin Chen