From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A6CDA27466A; Fri, 7 Aug 2026 15:24:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786116255; cv=none; b=H3Q8pJxysoI3801IG7tiqjcJ3IW4RkwgMitz08LEClfz4w33jkwSpEm+5V0+P/oVusCRM+T9TeTvq43HD5n56+SH7He4wb9pkK6ueOQkG/8bC7ZpEnzA0g5uPY9Iqz0fzWVDH18edtmXfK14PvAjwcIUFNGiHNFe2/buKW0AeXk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786116255; c=relaxed/simple; bh=DJRy5GHNnFxelIaVDuqOBXRPXB9olOVZri6gFMdNbZU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Am6drZ4GjXfKiZKXhQTsFdliOVaIjmfbrRBB3pWIYZEg9h6jUiD61rHawJdR161kEvm/GjOO8L8G/FAmmst0iIym1bXryxD2w2o/392RW6Ux92oEJyzhVNuGrlexejNcoK0Ee54xxp4zG5cesvEdGrXdnrGsLgHtEf5ToOt52nM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HAx2IwG1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HAx2IwG1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D7421F00A3F; Fri, 7 Aug 2026 15:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786116254; bh=hbSDSW3gkKEK1ITH/0Pc9vbfjyqh0eR0Q/tXhC8PF8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HAx2IwG1M+cW0LjvBI3IOxi4hVKhbUQZ+FuJuHkRtQK1pNs+fLKc/YdXyzrdYTIPE xcsaLH/1REUk2Dqt69l7lZqwywAnyIpelvZzajtBOPJUeDHVGhAYmJnSye1DRcBPr5 fZQwwIvAZgkZTkzeEJL3H/fNlVOYhhnF8cGZixlA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Haidar Lee , Mark Brown Subject: [PATCH 6.6 113/261] ASoC: tas2562: fix DVC coefficient write order Date: Fri, 7 Aug 2026 16:37:50 +0200 Message-ID: <20260807143417.816391109@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143415.358597922@linuxfoundation.org> References: <20260807143415.358597922@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Haidar Lee commit 8e957e4907c58e9ca944f98799524f2bbb9cf68a upstream. The TAS2562 applies the 32-bit digital volume coefficient to the playback path when the last byte, DVC_CFG4 (book 0 page 2 reg 0x0F), is written. tas2562_volume_control_put() wrote DVC_CFG4 first and DVC_CFG1 (the MSB) last, so every volume change latched a value made of the previous coefficient's upper three bytes combined with the new LSB; the remaining bytes only took effect on the next volume change. In practice the control was unusable: the first setting after power-on always played at roughly 0 dB no matter what value was requested (the chip's default upper bytes were still latched), and most subsequent changes muted the output entirely or produced a distorted, over-unity gain. Verified on a TAS2562 (ADLINK OSM-520 / MT8189 board) by tracing the I2C writes with ftrace and by writing the same coefficients manually in both byte orders: written MSB-first the register block behaves exactly as the driver expects, LSB-first reproduces the broken behaviour. Write the bytes MSB first with DVC_CFG4 last so the complete new coefficient is latched atomically. Fixes: bf726b1c86f2 ("ASoC: tas2562: Add support for digital volume control") Cc: stable@vger.kernel.org Signed-off-by: Haidar Lee Link: https://patch.msgid.link/20260715-tas2562-dvc-fix-v1-1-072b13901b20@adlinktech.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- sound/soc/codecs/tas2562.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) --- a/sound/soc/codecs/tas2562.c +++ b/sound/soc/codecs/tas2562.c @@ -476,20 +476,27 @@ static int tas2562_volume_control_put(st u32 reg_val; reg_val = float_vol_db_lookup[ucontrol->value.integer.value[0]/2]; - ret = snd_soc_component_write(component, TAS2562_DVC_CFG4, - (reg_val & 0xff)); - if (ret) - return ret; - ret = snd_soc_component_write(component, TAS2562_DVC_CFG3, - ((reg_val >> 8) & 0xff)); + /* + * The device applies the 32-bit coefficient to the playback path on + * the write to DVC_CFG4 (the LSB, book 0 page 2 reg 0x0F), so the + * bytes must be written MSB first and DVC_CFG4 last. Writing CFG4 + * first latches a mix of the previous coefficient's upper bytes and + * the new LSB instead of the requested value. + */ + ret = snd_soc_component_write(component, TAS2562_DVC_CFG1, + ((reg_val >> 24) & 0xff)); if (ret) return ret; ret = snd_soc_component_write(component, TAS2562_DVC_CFG2, ((reg_val >> 16) & 0xff)); if (ret) return ret; - ret = snd_soc_component_write(component, TAS2562_DVC_CFG1, - ((reg_val >> 24) & 0xff)); + ret = snd_soc_component_write(component, TAS2562_DVC_CFG3, + ((reg_val >> 8) & 0xff)); + if (ret) + return ret; + ret = snd_soc_component_write(component, TAS2562_DVC_CFG4, + (reg_val & 0xff)); if (ret) return ret;