[PATCH 3/3] hwmon: (coretemp) Refine TjMax detection

From: Guenter Roeck
Date: Sat Nov 09 2013 - 12:51:51 EST


Intel's turbostat code uses only 7 bits from MSR_IA32_TEMPERATURE_TARGET to
read TjMax, and also only accepts it if the reported temperature is at least
85 degrees C. Play safe and do the same.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/hwmon/coretemp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index cde4e47..310ce19 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -368,12 +368,12 @@ static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
if (cpu_has_tjmax(c))
dev_warn(dev, "Unable to read TjMax from CPU %u\n", id);
} else {
- val = (eax >> 16) & 0xff;
+ val = (eax >> 16) & 0x7f;
/*
* If the TjMax is not plausible, an assumption
* will be used
*/
- if (val) {
+ if (val >= 85) {
dev_dbg(dev, "TjMax is %d degrees C\n", val);
return val * 1000;
}
--
1.7.9.7

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