When the controller fails to provide an RPM reading within the alloted
time; the driver returns -ETIMEDOUT and no file contents.
Signed-off-by: Patrick Venture <venture@xxxxxxxxxx>
---
drivers/hwmon/aspeed-pwm-tacho.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 48403a2115be..12b716b70ead 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -7,6 +7,7 @@
*/
#include <linux/clk.h>
+#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
#include <linux/hwmon.h>
@@ -494,7 +495,7 @@ static u32 aspeed_get_fan_tach_ch_measure_period(struct aspeed_pwm_tacho_data
return clk / (clk_unit * div_h * div_l * tacho_div * tacho_unit);
}
-static u32 aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
+static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
u8 fan_tach_ch)
{
u32 raw_data, tach_div, clk_source, sec, val;
@@ -510,6 +511,9 @@ static u32 aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
msleep(sec);
regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val);
+ if (!(val & RESULT_STATUS_MASK))
+ return -ETIMEDOUT;
+
raw_data = val & RESULT_VALUE_MASK;
tach_div = priv->type_fan_tach_clock_division[type];
tach_div = 0x4 << (tach_div * 2);
@@ -561,12 +565,14 @@ static ssize_t show_rpm(struct device *dev, struct device_attribute *attr,
{
struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
int index = sensor_attr->index;
- u32 rpm;
+ int rpm;
struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
rpm = aspeed_get_fan_tach_ch_rpm(priv, index);
+ if (rpm < 0)
+ return rpm;
- return sprintf(buf, "%u\n", rpm);
+ return sprintf(buf, "%d\n", rpm);
}
static umode_t pwm_is_visible(struct kobject *kobj,
--
2.13.0.219.gdb65acc882-goog
--
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