Commit c0940e95 authored Apr 30, 2014 by Guenter Roeck

Revert "hwmon: (coretemp) Refine TjMax detection"

This reverts commit 9fb6c9c7.

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: 9fb6c9c7 hwmon: (coretemp) Refine TjMax detection
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

parent d1db0eea

drivers/hwmon/coretemp.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -365,12 +365,12 @@ 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;
		}

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