From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794460440; b=hw8mEszzsg2LeJk23Pf+douKU6a1WgicZzV7m/8eq+B7+W3M3g2VZnkA6gWJuuEkg34t vytxV5jL6RFaVRvToQiMJnKjS+XgCzy/8qkvgVRu6ePOpeIW3yzxsuxcDz/qUs9mvc80m 6HlBqJmv+hPVXHJ1MsapsdLguomWRfgbfJBSRFccYPEY/j+xNLWrp64n0Fd5SzhQUGohj YmHxlU4g6GyZBdgypBtC0JopK+VVqOtqZS9iu9vgNMISV2jCTfgjW0sET1Nal1oEeZ6zG q+h8LkeYgkNc0PD6vNuhvblQnU0PB3eEy+VKV5li6U+JUyi86fKjFzjaUEwVuoczTew== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794460440; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=utZFr/1vsGaIWAcYvlUcCja4DhFBelL8WryUEmKJPz4=; b=10FVi7yvlQOZZdNbHuJ3+YY8GMe1Ei3/7EKVN+lxb07oqOwCmvAM3vTfI+C6MN/Ouppa +RGx/BHLD/7YwFIQAGw8G/7uVQualEqmDlOLxOtB57NUrxEGVY+0hVjmSESGm4uzpa3Fi dTeZhUE1ZPsTZaS1hE1eCwHgzvhLowHmw1B7ndpWVAnpa+eoNYle4EJ+LmvubrySWZBPb koPlN8ExfXq3XrDXzE4179tLsGlpDz0fXD5dW6pCRGoVcuuct/58CHQTr9aWIQhBzbr/R /C/ks2FMwMcGD2eL5vjNL1RGDilXjws8s0b+9J3M7DUX3tmcy29XsK4al9GsD5pxB+Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=f9o1M7L6; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D50D606A31C for ; Thu, 12 Nov 2026 05:14:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=f9o1M7L6 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2F341F00A07; Thu, 12 Nov 2026 05:13:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794460440; bh=utZFr/1vsGaIWAcYvlUcCja4DhFBelL8WryUEmKJPz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f9o1M7L641xi52K6wWAstVXFiEafT0QZtkwq+IN68dJwxYhLL5MmdH2xnKhE//jhP OPfYSuzhq8Oxkemt9oqmbjDa6vVeX9sxB5a/leijAKwIqnV1tv18CkKpiY5Jekd2te KfA4l7Gj0+LBmhLvQsrs1fiJqFOEXLBPHbPCDjqjlMaSoWmwa7vASNUVn7iQCwsW0/ 7CM9ho+wrPHpDD8AKZCE/P7AXahYCwdz5e6/en7sID6n86E1D9bLgMQ9Qsy+x/5JiE +xENSLoi1VrwNVN6MyhF9yKHil/H1cHR4aJRLCxFatP4rhs8UxAWL/C8ivX4JluqK5 YteSTWo8u1hMg== From: Sasha Levin To: stable@vger.kernel.org Cc: Javier Carrasco , Guenter Roeck , Sasha Levin Subject: [PATCH 6.18.y 2/3] hwmon: chipcap2: serialize access to the alarm indicators Date: Thu, 12 Nov 2026 00:13:56 -0500 Message-ID: <20261112051344.2630398-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261112051344.2630398-1-sashal@kernel.org> References: <20261109200334-failed-6.18-8c02722be2ca@kernel.org> <20261112051344.2630398-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Javier Carrasco [ Upstream commit bed5f0c075eb99442fca6a61c009a32752eceda2 ] low_alarm and high_alarm are accessed from the threaded interrupt handlers and from sysfs without any locking, which can lead to lost alarms. Add a mutex to serialize the access to the alarm indicators and to process_irqs, which the handlers use to decide whether an interrupt belongs to an ongoing operation. Fixes: 3af350929e75 ("hwmon: Add support for Amphenol ChipCap 2") Cc: stable@vger.kernel.org Signed-off-by: Javier Carrasco Link: https://patch.msgid.link/20261014-chipcap2_locks-v3-10-27ebfc2c5b9e@gmail.com [groeck: Dropped obsolete 'Assisted-by: tag] Signed-off-by: Guenter Roeck Stable-dep-of: 8c02722be2ca ("hwmon: chipcap2: synchronize ready IRQ state") Signed-off-by: Sasha Levin --- drivers/hwmon/chipcap2.c | 58 +++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 21 deletions(-) diff --git a/drivers/hwmon/chipcap2.c b/drivers/hwmon/chipcap2.c index a3d5d99bd57ea..49df66728ae9d 100644 --- a/drivers/hwmon/chipcap2.c +++ b/drivers/hwmon/chipcap2.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -88,6 +89,8 @@ struct cc2_data { int irq_low; int irq_high; bool process_irqs; + /* protects process_irqs and the alarm indicators */ + struct mutex irq_lock; bool regulator_enabled; }; @@ -119,7 +122,8 @@ static int cc2_enable(struct cc2_data *data) /* exclusive regulator, check in case a disable failed */ if (data->regulator_enabled) { - data->process_irqs = true; + scoped_guard(mutex, &data->irq_lock) + data->process_irqs = true; return 0; } @@ -134,7 +138,8 @@ static int cc2_enable(struct cc2_data *data) usleep_range(CC2_STARTUP_TIME_US, CC2_STARTUP_TIME_US + 125); - data->process_irqs = true; + scoped_guard(mutex, &data->irq_lock) + data->process_irqs = true; return 0; } @@ -151,7 +156,8 @@ static void cc2_disable(struct cc2_data *data) synchronize_irq(data->irq_high); /* ignore alarms triggered by voltage toggling when powering up */ - data->process_irqs = false; + scoped_guard(mutex, &data->irq_lock) + data->process_irqs = false; /* exclusive regulator, check in case an enable failed */ if (!data->regulator_enabled) @@ -502,10 +508,12 @@ static irqreturn_t cc2_low_interrupt(int irq, void *data) { struct cc2_data *cc2 = data; - if (cc2->process_irqs) { - hwmon_notify_event(cc2->hwmon, hwmon_humidity, - hwmon_humidity_min_alarm, 0); - cc2->rh_alarm.low_alarm = true; + scoped_guard(mutex, &cc2->irq_lock) { + if (cc2->process_irqs) { + hwmon_notify_event(cc2->hwmon, hwmon_humidity, + hwmon_humidity_min_alarm, 0); + cc2->rh_alarm.low_alarm = true; + } } return IRQ_HANDLED; @@ -515,10 +523,12 @@ static irqreturn_t cc2_high_interrupt(int irq, void *data) { struct cc2_data *cc2 = data; - if (cc2->process_irqs) { - hwmon_notify_event(cc2->hwmon, hwmon_humidity, - hwmon_humidity_max_alarm, 0); - cc2->rh_alarm.high_alarm = true; + scoped_guard(mutex, &cc2->irq_lock) { + if (cc2->process_irqs) { + hwmon_notify_event(cc2->hwmon, hwmon_humidity, + hwmon_humidity_max_alarm, 0); + cc2->rh_alarm.high_alarm = true; + } } return IRQ_HANDLED; @@ -534,11 +544,13 @@ static int cc2_humidity_min_alarm_status(struct cc2_data *data, long *val) if (ret < 0) return ret; - if (data->rh_alarm.low_alarm) { - *val = (measurement < min_hyst) ? 1 : 0; - data->rh_alarm.low_alarm = *val; - } else { - *val = 0; + scoped_guard(mutex, &data->irq_lock) { + if (data->rh_alarm.low_alarm) { + *val = (measurement < min_hyst) ? 1 : 0; + data->rh_alarm.low_alarm = *val; + } else { + *val = 0; + } } return 0; @@ -554,11 +566,13 @@ static int cc2_humidity_max_alarm_status(struct cc2_data *data, long *val) if (ret < 0) return ret; - if (data->rh_alarm.high_alarm) { - *val = (measurement > max_hyst) ? 1 : 0; - data->rh_alarm.high_alarm = *val; - } else { - *val = 0; + scoped_guard(mutex, &data->irq_lock) { + if (data->rh_alarm.high_alarm) { + *val = (measurement > max_hyst) ? 1 : 0; + data->rh_alarm.high_alarm = *val; + } else { + *val = 0; + } } return 0; @@ -721,6 +735,8 @@ static int cc2_probe(struct i2c_client *client) i2c_set_clientdata(client, data); + mutex_init(&data->irq_lock); + data->client = client; data->regulator = devm_regulator_get_exclusive(dev, "vdd"); -- 2.53.0