hwmon: (coretemp) Do not return -EAGAIN for low temperatures

Some Intel CPUs do not set the 'valid' bit in IA32_THERM_STATUS if the
temperature is too low to be measured. This condition will not change until
the CPU is hot enough for its temperature to be measured. Returning an error
in such conditions is not very useful. Drop checking the valid bit and just
return the reported temperature instead.

Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 310ce193bbd0faf07d57f0686d5f7ba8dfbe42f0..6e0579e805383671491bdfc2d3fd30b3566d87f1 100644 (file)
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -177,18 +177,19 @@ static ssize_t show_temp(struct device *dev,
        /* Check whether the time interval has elapsed */
        if (!tdata->valid || time_after(jiffies, tdata->last_updated + HZ)) {
                rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
-               tdata->valid = 0;
-               /* Check whether the data is valid */
-               if (eax & 0x80000000) {
-                       tdata->temp = tdata->tjmax -
-                                       ((eax >> 16) & 0x7f) * 1000;
-                       tdata->valid = 1;
-               }
+               /*
+                * Ignore the valid bit. In all observed cases the register
+                * value is either low or zero if the valid bit is 0.
+                * Return it instead of reporting an error which doesn't
+                * really help at all.
+                */
+               tdata->temp = tdata->tjmax - ((eax >> 16) & 0x7f) * 1000;
+               tdata->valid = 1;
                tdata->last_updated = jiffies;
        }
 
        mutex_unlock(&tdata->update_lock);
-       return tdata->valid ? sprintf(buf, "%d\n", tdata->temp) : -EAGAIN;
+       return sprintf(buf, "%d\n", tdata->temp);
 }
 
 struct tjmax_pci {