From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C3CE726E14A; Tue, 25 Feb 2025 14:41:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740494518; cv=none; b=Fb0OJLIml8SjinFw8hJV3PZ6sAtyxfL+aiM0CC/8xFY3F0bJBJri964JhBaoxjtJn/ax6R/s4ZFyDQU6UKH6fqaLS+MlYyKbUR6/Xnwo7pLpubdi9WJAJk+mKVVKXWwlk88iVCk8hvO+0v2lBbbRRClsrpNZUc6VKMcWpGzM7rk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740494518; c=relaxed/simple; bh=XGd1XNQmqCz8KaVN0OhhQX9JZety99RRX4T3g5Moydo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tzX9wlr/eG3vgtAMRHX/tSx9afhDG6oX5mScMzpWqFFs1XbDOG1PE8CsYTSlCBxpXGP+ya8ahLw6O+dbDcB5XH6l/lvTNJvwsI6dWCeeAxXxOmSKql2XoeKlxFbdNtLBOaJNN8L+q8D1REVJUoHKf01zc6cscki5IDauD9gg70M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=kr2oUmfc; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="kr2oUmfc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1740494515; bh=XGd1XNQmqCz8KaVN0OhhQX9JZety99RRX4T3g5Moydo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kr2oUmfcJQuKh8aILaNXIdCk1gSqWLuexXQKP5GEN6nIHKFq188/m0uvAxW/kwaEL BcewF+ymErrazigNMoAwodNtf56IjFDJQZuuIr+zpzzBPfKYUBz2V11BhYWsPYZV24 rPSymGxo2avto4L43NxPAKZf1/BuJJbHx4lsNJGF+67u7gCM2pcXJlpzMSXWIEIioC 5DRWAeVnH/tnCPT4RTKex9V6MykG2hjKoQaTPhBECZyUG/MCZBNP5YaEgBE5sTJ/hj D/QfV/e0loBOt5//Fe5eOCwsyLaBFnUo4PczRljtEWv/mqUaMz8Kiv7+P/9AlCMXv2 Y8RJGKDAeTfRw== Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id 2693717E1016; Tue, 25 Feb 2025 15:41:54 +0100 (CET) Message-ID: <173e41bd-4fa0-4b54-8739-546536ad7c3b@collabora.com> Date: Tue, 25 Feb 2025 15:41:53 +0100 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/8] ASoC: mediatek: mt8188: Treat DMIC_GAINx_CUR as non-volatile To: =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , Matthias Brugger , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Trevor Wu Cc: kernel@collabora.com, linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org References: <20250225-genio700-dmic-v2-0-3076f5b50ef7@collabora.com> <20250225-genio700-dmic-v2-3-3076f5b50ef7@collabora.com> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20250225-genio700-dmic-v2-3-3076f5b50ef7@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Il 25/02/25 15:33, Nícolas F. R. A. Prado ha scritto: > The DMIC_GAINx_CUR registers contain the current (as in present) gain of > each DMIC. During capture, this gain will ramp up until a target value > is reached, and therefore the register is volatile since it is updated > automatically by hardware. > > However, after capture the register's value returns to the value that > was written to it. So reading these registers returns the current gain, > and writing configures the initial gain for every capture. > > From an audio configuration perspective, reading the instantaneous gain > is not really useful. Instead, reading back the initial gain that was > configured is the desired behavior. For that reason, consider the > DMIC_GAINx_CUR registers as non-volatile, so the regmap's cache can be > used to retrieve the values, rather than requiring pm runtime resuming > the device. > > Signed-off-by: Nícolas F. R. A. Prado Reviewed-by: AngeloGioacchino Del Regno