From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93E43C433DB for ; Thu, 25 Mar 2021 11:31:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FAE56023F for ; Thu, 25 Mar 2021 11:31:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230191AbhCYLbY (ORCPT ); Thu, 25 Mar 2021 07:31:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:35200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231384AbhCYL3W (ORCPT ); Thu, 25 Mar 2021 07:29:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B367861A42; Thu, 25 Mar 2021 11:27:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616671651; bh=5K42GOL0CTGzkR5Zq2OyJCjPN5ux3s+opHFWr23aX4k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NxaNLRXLYo0pUcK0AcRdkU7wPAaGWZr7iM4u2xAxvHXpwMKjuBtkrbJ5UL3YO5Kdh bFJ41XUbkRtXICourSNH3bCYnMEC6OvLdlCce1SPwb/G9U8dgbUp6HaCd4ixcQU9Jq LGZNeXlEax+Ie0GZMONVvTJLAAF3n7VcFB86fzgR33HoaHo6cfl0i4GYDPlXU+1Fh3 bWpcLJryujukzOlwo5cj323VAua37FBi8wf2SYhruW+qyOM45Q8g02lqRBPxuFsJr1 Prv7tp/8c4Il16027VtDu/H+46FTqsutqPFj4svtMN6MiCR8rNYGpnsD7jSU12e0dT y3yjHz2RK9tXQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Benjamin Rood , Fabio Estevam , Mark Brown , Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.19 05/20] ASoC: sgtl5000: set DAP_AVC_CTRL register to correct default value on probe Date: Thu, 25 Mar 2021 07:27:09 -0400 Message-Id: <20210325112724.1928174-5-sashal@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210325112724.1928174-1-sashal@kernel.org> References: <20210325112724.1928174-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Benjamin Rood [ Upstream commit f86f58e3594fb0ab1993d833d3b9a2496f3c928c ] According to the SGTL5000 datasheet [1], the DAP_AVC_CTRL register has the following bit field definitions: | BITS | FIELD | RW | RESET | DEFINITION | | 15 | RSVD | RO | 0x0 | Reserved | | 14 | RSVD | RW | 0x1 | Reserved | | 13:12 | MAX_GAIN | RW | 0x1 | Max Gain of AVC in expander mode | | 11:10 | RSVD | RO | 0x0 | Reserved | | 9:8 | LBI_RESP | RW | 0x1 | Integrator Response | | 7:6 | RSVD | RO | 0x0 | Reserved | | 5 | HARD_LMT_EN | RW | 0x0 | Enable hard limiter mode | | 4:1 | RSVD | RO | 0x0 | Reserved | | 0 | EN | RW | 0x0 | Enable/Disable AVC | The original default value written to the DAP_AVC_CTRL register during sgtl5000_i2c_probe() was 0x0510. This would incorrectly write values to bits 4 and 10, which are defined as RESERVED. It would also not set bits 12 and 14 to their correct RESET values of 0x1, and instead set them to 0x0. While the DAP_AVC module is effectively disabled because the EN bit is 0, this default value is still writing invalid values to registers that are marked as read-only and RESERVED as well as not setting bits 12 and 14 to their correct default values as defined by the datasheet. The correct value that should be written to the DAP_AVC_CTRL register is 0x5100, which configures the register bits to the default values defined by the datasheet, and prevents any writes to bits defined as 'read-only'. Generally speaking, it is best practice to NOT attempt to write values to registers/bits defined as RESERVED, as it generally produces unwanted/undefined behavior, or errors. Also, all credit for this patch should go to my colleague Dan MacDonald for finding this error in the first place. [1] https://www.nxp.com/docs/en/data-sheet/SGTL5000.pdf Signed-off-by: Benjamin Rood Reviewed-by: Fabio Estevam Link: https://lore.kernel.org/r/20210219183308.GA2117@ubuntu-dev Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- sound/soc/codecs/sgtl5000.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index 7c0a06b487f7..17255e9683f5 100644 --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -71,7 +71,7 @@ static const struct reg_default sgtl5000_reg_defaults[] = { { SGTL5000_DAP_EQ_BASS_BAND4, 0x002f }, { SGTL5000_DAP_MAIN_CHAN, 0x8000 }, { SGTL5000_DAP_MIX_CHAN, 0x0000 }, - { SGTL5000_DAP_AVC_CTRL, 0x0510 }, + { SGTL5000_DAP_AVC_CTRL, 0x5100 }, { SGTL5000_DAP_AVC_THRESHOLD, 0x1473 }, { SGTL5000_DAP_AVC_ATTACK, 0x0028 }, { SGTL5000_DAP_AVC_DECAY, 0x0050 }, -- 2.30.1