From: Guenter Roeck <linux@roeck-us.net>
To: linux-hwmon@vger.kernel.org
Cc: Jean Delvare <jdelvare@suse.com>,
jan.kundrat@cesnet.cz, kubernat@cesnet.cz,
Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 6/7] hwmon: (max31790) Detect and report zero fan speed
Date: Wed, 26 May 2021 08:40:21 -0700 [thread overview]
Message-ID: <20210526154022.3223012-7-linux@roeck-us.net> (raw)
In-Reply-To: <20210526154022.3223012-1-linux@roeck-us.net>
If a fan is not running or not connected, of if fan monitoring is disabled,
the fan count register returns a fixed value of 0xffe0. So far this is then
translated to a RPM value larger than 0. Since this is misleading and does
not really make much sense, report a fan RPM of 0 in this situation.
Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/hwmon/max31790.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 8e4fd9b7c889..91fe419b596c 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -40,6 +40,8 @@
#define FAN_RPM_MIN 120
#define FAN_RPM_MAX 7864320
+#define FAN_COUNT_REG_MAX 0xffe0
+
#define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \
((60 * (sr) * 8192) / ((reg) >> 4)) : \
FAN_RPM_MAX)
@@ -175,7 +177,10 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
return 0;
case hwmon_fan_input:
sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
- rpm = RPM_FROM_REG(data->tach[channel], sr);
+ if (data->tach[channel] == FAN_COUNT_REG_MAX)
+ rpm = 0;
+ else
+ rpm = RPM_FROM_REG(data->tach[channel], sr);
*val = rpm;
return 0;
case hwmon_fan_target:
--
2.25.1
next prev parent reply other threads:[~2021-05-26 15:40 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 15:40 [PATCH 0/7] hwmon: (max31790) Fixes and improvements Guenter Roeck
2021-05-26 15:40 ` [PATCH 1/7] hwmon: (max31790) Fix fan speed reporting for fan7..12 Guenter Roeck
2021-06-02 12:27 ` Jan Kundrát
2021-05-26 15:40 ` [PATCH 2/7] hwmon: (max31790) Report correct current pwm duty cycles Guenter Roeck
2021-06-01 7:51 ` Václav Kubernát
2021-06-02 12:36 ` Jan Kundrát
2021-05-26 15:40 ` [PATCH 3/7] hwmon: (max31790) Fix pwmX_enable attributes Guenter Roeck
2021-06-01 8:01 ` Václav Kubernát
2021-06-02 10:47 ` Guenter Roeck
2021-06-02 12:44 ` Jan Kundrát
2021-05-26 15:40 ` [PATCH 4/7] hwmon: (max31790) Add support for fanX_enable attributes Guenter Roeck
2021-06-01 8:02 ` Václav Kubernát
2021-06-02 13:04 ` Jan Kundrát
2021-06-02 16:43 ` Guenter Roeck
2021-05-26 15:40 ` [PATCH 5/7] hwmon: (max31790) Clear fan fault after reporting it Guenter Roeck
2021-06-01 8:08 ` Václav Kubernát
2021-05-26 15:40 ` Guenter Roeck [this message]
2021-06-01 8:11 ` [PATCH 6/7] hwmon: (max31790) Detect and report zero fan speed Václav Kubernát
2021-05-26 15:40 ` [PATCH 7/7] hwmon: (max31790) Add support for fanX_min attributes Guenter Roeck
2021-06-01 8:19 ` Václav Kubernát
2021-06-01 8:29 ` [PATCH 0/7] hwmon: (max31790) Fixes and improvements Václav Kubernát
2021-06-01 12:08 ` Guenter Roeck
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