From: Guenter Roeck Date: Wed, 30 Apr 2014 21:08:14 +0000 (-0700) Subject: Revert "hwmon: (coretemp) Refine TjMax detection" X-Git-Tag: submit/tizen_common/20140730.172411~789 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f35f0047951663702d21e430c9e986a22c4ddd69;p=profile%2Fivi%2Fkernel-x86-ivi.git Revert "hwmon: (coretemp) Refine TjMax detection" commit c0940e95f7a78be0525c8d31df0b1f71e149e57e upstream. This reverts commit 9fb6c9c73b11bef65ba80a362547fd116c1e1c9d. Tjmax on some Intel CPUs is below 85 degrees C. One known example is L5630 with Tjmax of 71 degrees C. There are other Xeon processors with Tjmax of 70 or 80 degrees C. Also, the Intel IA32 System Programming document states that the temperature target is in bits 23:16 of MSR 0x1a2 (MSR_TEMPERATURE_TARGET), which is 8 bits, not 7. So even if turbostat uses similar checks to validate Tjmax, there is no evidence that the checks are actually required. On the contrary, the checks are known to cause problems and therefore need to be removed. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=75071. Fixes: 9fb6c9c hwmon: (coretemp) Refine TjMax detection Reviewed-by: Jean Delvare Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index bbb0b0d..1599310 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -369,12 +369,12 @@ 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) & 0x7f; + val = (eax >> 16) & 0xff; /* * If the TjMax is not plausible, an assumption * will be used */ - if (val >= 85) { + if (val) { dev_dbg(dev, "TjMax is %d degrees C\n", val); return val * 1000; }