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 A24AA5476DF for ; Wed, 9 Sep 2026 11:40:51 +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=1788954052; cv=none; b=PKO6JkkxuGU3E/FYPGvPTTon+g9gMBvTGqc6NG9VsGg3vRWIUaWolL55gDlwt37GIKrLG04EtQxxMtdw2e0xmZcZjkUsSrLkxwXI4S28OhBpaO83CCGJOaANOu5P+sK8rN/1ydvh1HNlIaH43qAncMpVkc/hn3VrTmZYYZqYioc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788954052; c=relaxed/simple; bh=O0UsgYXzvFML8jffIZP15V3Z8VumDVCiZ3v82Mv99bM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cC5WWnFuY6TTGBaWu6TnuqAc52znmmsgpmvP0DILEg1TMrmz/3xsciw79sMAw3D8ma3aeQKlfzIQyLVqFFmxkPvy4ihI13331dbsTzvCpZPeY8lYbXnoiSQlK3gpyT4SiQuR35Ksq3L1zdKomGQPrAf6ngtwmT3hgyJHbotilHI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eki/KqZu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eki/KqZu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBA4D1F00A3D; Wed, 9 Sep 2026 11:40:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788954051; bh=1AXGHq0rEZM+YoJ2qlq316RAZyYzUQjeRA9ZperhHyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eki/KqZukvcceSCqoDOcSNFDW2qEuTdQT33cQI24LKi4wwDBrzLAX6npbTkjRkvZj wXXMPf8c8ylb9DFLNGqItje3EHNVJtNnmdk1q5P8vM7Li9NvzBqeXvsS7B+bPMW94K WIXo7zRup460NmWXSf+EpX7N85kjjp4ifQX/iRoOLlZTGLo/vU/ynQo6h86eSo5QSh /tPpIRqcGz3vLaRng7Tb7PKgAuvmThZ09yBLbVZUDamrCu5PhFue5Pmgqtd3XhL+6W LrLhQ89jtCNTN4gHfbynychjUJ35b5KdQlhV8TvPKm4jIwk4R++wza8mujdsXFbN7D 8NqKm2CVWD9wg== From: Sasha Levin To: stable@vger.kernel.org Cc: Jianing Li , Sebastian Reichel , Sasha Levin Subject: [PATCH 5.15.y 2/2] power: supply: max17040: propagate register read errors Date: Wed, 9 Sep 2026 07:40:48 -0400 Message-ID: <20260909114048.1917822-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260909114048.1917822-1-sashal@kernel.org> References: <2026090315-stimulate-nanny-a782@gregkh> <20260909114048.1917822-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jianing Li [ Upstream commit 659cc3d8d5ef246263873fce72c8cadeeed073cc ] max17040_get_vcell() and max17040_get_soc() ignore errors returned by regmap_read(). When an I2C transfer fails, the uninitialized register value is converted and reported to userspace as a valid voltage or state of charge. The polling worker can also replace the cached state of charge with the bogus value and emit a spurious change event. Propagate read errors through the power supply get_property callback and keep the last valid cached state of charge when polling fails. Fixes: c6f4a42de60b ("Add MAX17040 Fuel Gauge driver") Cc: stable@vger.kernel.org Signed-off-by: Jianing Li Link: https://patch.msgid.link/20260727064825.948-1-m13940358460@163.com Signed-off-by: Sebastian Reichel Signed-off-by: Sasha Levin --- drivers/power/supply/max17040_battery.c | 26 ++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c index 13e82a1ab2aee..f82c26ebb33aa 100644 --- a/drivers/power/supply/max17040_battery.c +++ b/drivers/power/supply/max17040_battery.c @@ -190,8 +190,11 @@ static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell) static int max17040_get_vcell(struct max17040_chip *chip) { u32 vcell; + int ret; - regmap_read(chip->regmap, MAX17040_VCELL, &vcell); + ret = regmap_read(chip->regmap, MAX17040_VCELL, &vcell); + if (ret) + return ret; return max17040_raw_vcell_to_uvolts(chip, vcell); } @@ -199,8 +202,11 @@ static int max17040_get_vcell(struct max17040_chip *chip) static int max17040_get_soc(struct max17040_chip *chip) { u32 soc; + int ret; - regmap_read(chip->regmap, MAX17040_SOC, &soc); + ret = regmap_read(chip->regmap, MAX17040_SOC, &soc); + if (ret) + return ret; return soc >> (chip->quirk_double_soc ? 9 : 8); } @@ -259,7 +265,11 @@ static int max17040_get_of_data(struct max17040_chip *chip) static void max17040_check_changes(struct max17040_chip *chip) { - chip->soc = max17040_get_soc(chip); + int soc; + + soc = max17040_get_soc(chip); + if (soc >= 0) + chip->soc = soc; } static void max17040_queue_work(struct max17040_chip *chip) @@ -393,10 +403,16 @@ static int max17040_get_property(struct power_supply *psy, val->intval = max17040_get_online(chip); break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: - val->intval = max17040_get_vcell(chip); + ret = max17040_get_vcell(chip); + if (ret < 0) + return ret; + val->intval = ret; break; case POWER_SUPPLY_PROP_CAPACITY: - val->intval = max17040_get_soc(chip); + ret = max17040_get_soc(chip); + if (ret < 0) + return ret; + val->intval = ret; break; case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: val->intval = chip->low_soc_alert; -- 2.53.0