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=1794581282; b=ftGZ4vRfkh4EAT/4SPCB6FDdGfRMBj3lPLayuojLE2T+7LHPTCdWW8b0E2J0UxwHN8DP ZjBZ1dn430+SNZWnFI7OhKVN6j8LdyZHLmeF4V8UVl4mJ2SfKGbvvZISl5e0VHPfS9aJc 0l8DKhmttJhcDvogOpOIAVX5toUKfWHq4rqa3zZ7HnpiJf1C1NENTxdBGBHrBfTVS6cER S+VHmarhgi/HyUyUWsx2DYE3xhkpfZNZBK2AmFLMv931B1ykMQredvU0sh1+i+Wmih4dx JS1EzxhScW094Ea4NDhOpWS0x9RfmnvbKZjHjFlPGy70iCLsRfhguyD5feIyPLdmcDA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794581282; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=wUd59vy+t7BNnxnUhr2fKkMzMsXeEKOtpU9SL8Q2YUs=; b=2J4ufimj9rh5QnOly9wf23s3Q0a7wkMqy9UYeXzZWWXYxrOaDyXQpplDcD5YlN1DWw/R +FPulx/7Dza9WOg6ZueSh4ITYcsejHZBJgrPf64GERMDOw1D5hcXUYtaICUp9BUYCU3TF R7LbTxUNoS0ovWzMGbPIS/z68495SDb1lGSXl8eIHvrh6uB71+Omvx/ZCE/T5uH5cr29H Kem2AdsyisItwN8WBWyOLSZUwRFjex/LmsU1LWoq+23HpkEM3ueZTWu0dNwQ3lOiqHEK2 j8X5Gd+cYYX8fF4BwagoirMzPbSyvSR8ZqsPPAP+9IiKPsP/IPojDZiz4qVtMYTtwaA== 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=IMhujO9J; 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 39059606A330 for ; Fri, 13 Nov 2026 14:48:02 +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=IMhujO9J Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8ACDE1F000C8; Fri, 13 Nov 2026 14:48:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794581282; bh=wUd59vy+t7BNnxnUhr2fKkMzMsXeEKOtpU9SL8Q2YUs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IMhujO9J2TYsglNOesa1ksliZpYbQ539pLYHh84KsaDdhMuHp4MJIGmr6gANMSOOF z57yxOMERERjSIgdkzA5TW7GVJXnPJeRMGKauYgKZOreN8h/6SHZX9u+6LBXFHuRyO cnPEZyzLoj+vOCtmj2fb16HT4juVPItBFyG4cmyhq9CniIE19XvouTcm630rSn87TW JLxSW4fJv6DZhbQZ+4NWbxwXkbv0dKuGQwZPf2vSjH7eBJP55wRVnasRlh4XbvMjvH A1+NQAI+lck6iW+aCAAP52EsqVPscSS3Rvx3MrLUeeZwuWC9kKD1Y/QLmYyZq2Gn7P sZlzkXDi2az2A== From: Sasha Levin To: stable@vger.kernel.org Cc: Javier Carrasco , Guenter Roeck , Sasha Levin Subject: [PATCH 6.18.y 2/2] hwmon: chipcap2: serialize access to the alarm indicators Date: Fri, 13 Nov 2026 09:47:59 -0500 Message-ID: <20261113135622.1498116-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261113135622.1498116-1-sashal@kernel.org> References: <20261109200332-failed-6.18-bed5f0c075eb@kernel.org> <20261113135622.1498116-1-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 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