summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/hwmon/coretemp7
-rw-r--r--drivers/hwmon/coretemp.c15
2 files changed, 19 insertions, 3 deletions
diff --git a/Documentation/hwmon/coretemp b/Documentation/hwmon/coretemp
index fa8776ab9b18..49c0d42dde86 100644
--- a/Documentation/hwmon/coretemp
+++ b/Documentation/hwmon/coretemp
@@ -49,9 +49,10 @@ tempX_label - Contains string "Core X", where X is processor
number. For Package temp, this will be "Physical id Y",
where Y is the package number.
-The TjMax temperature is set to 85 degrees C if undocumented model specific
-register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as
-(sometimes) documented in processor datasheet.
+On CPU models which support it, TjMax is read from a model-specific register.
+On other models, it is set to an arbitrary value based on weak heuristics.
+If these heuristics don't work for you, you can pass the correct TjMax value
+as a module parameter (tjmax).
Appendix A. Known TjMax lists (TBD):
Some information comes from ark.intel.com
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 256f70803eb3..5a41e9dda909 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -36,11 +36,20 @@
#include <linux/cpu.h>
#include <linux/pci.h>
#include <linux/smp.h>
+#include <linux/moduleparam.h>
#include <asm/msr.h>
#include <asm/processor.h>
#define DRVNAME "coretemp"
+/*
+ * force_tjmax only matters when TjMax can't be read from the CPU itself.
+ * When set, it replaces the driver's suboptimal heuristic.
+ */
+static int force_tjmax;
+module_param_named(tjmax, force_tjmax, int, 0444);
+MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
+
#define BASE_SYSFS_ATTR_NO 2 /* Sysfs Base attr no for coretemp */
#define NUM_REAL_CORES 16 /* Number of Real cores per cpu */
#define CORETEMP_NAME_LENGTH 17 /* String Length of attrs */
@@ -398,6 +407,12 @@ static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
}
}
+ if (force_tjmax) {
+ dev_notice(dev, "TjMax forced to %d degrees C by user\n",
+ force_tjmax);
+ return force_tjmax * 1000;
+ }
+
/*
* An assumption is made for early CPUs and unreadable MSR.
* NOTE: the calculated value may not be correct.
OpenPOWER on IntegriCloud