[PATCH 3.10 11/44] hwmon: (adm1029) Ensure the fan_div cache is updated in set_fan_div

From: Greg Kroah-Hartman
Date: Tue Jul 15 2014 - 20:17:53 EST

3.10-stable review patch. If anyone has any objections, please let me know.


From: Axel Lin <axel.lin@xxxxxxxxxx>

commit 1035a9e3e9c76b64a860a774f5b867d28d34acc2 upstream.

Writing to fanX_div does not clear the cache. As a result, reading
from fanX_div may return the old value for up to two seconds
after writing a new value.

This patch ensures the fan_div cache is updated in set_fan_div().

Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/hwmon/adm1029.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/hwmon/adm1029.c
+++ b/drivers/hwmon/adm1029.c
@@ -232,6 +232,9 @@ static ssize_t set_fan_div(struct device
/* Update the value */
reg = (reg & 0x3F) | (val << 6);

+ /* Update the cache */
+ data->fan_div[attr->index] = reg;
/* Write value */
ADM1029_REG_FAN_DIV[attr->index], reg);

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