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| author | Jean Delvare <khali@linux-fr.org> | 2011-09-16 21:24:02 +0200 |
|---|---|---|
| committer | Guenter Roeck <guenter.roeck@ericsson.com> | 2011-09-21 17:25:18 -0700 |
| commit | a45a8c8571c0be6a6bd72ae5a14255c26b14b504 (patch) | |
| tree | 47593c6b73c9a68dce03b57e7a387f94f441b8bb | |
| parent | 6bf9e9b09c3abb5447bbbf16c2d0cbe721e44f3f (diff) | |
| download | blackbird-op-linux-a45a8c8571c0be6a6bd72ae5a14255c26b14b504.tar.gz blackbird-op-linux-a45a8c8571c0be6a6bd72ae5a14255c26b14b504.zip | |
hwmon: (coretemp) Let the user force TjMax
On old CPUs (and even some recent Atom CPUs) TjMax can't be read from
the CPU registers, so it is guessed by the driver using a complex
heuristic which isn't reliable. So let users who know their CPU's
TjMax pass it as a module parameter.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "R, Durgadoss" <durgadoss.r@intel.com>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
| -rw-r--r-- | Documentation/hwmon/coretemp | 7 | ||||
| -rw-r--r-- | drivers/hwmon/coretemp.c | 15 |
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. |
