Commit 1becf035 authored Apr 22, 2016 by Srinivas Pandruvada Committed by Rafael J. Wysocki Apr 25, 2016

cpufreq: intel_pstate: Fix processing for turbo activation ratio

When the config TDP level is not nominal (level = 0), the MSR values for
reading level 1 and level 2 ratios contain power in low 14 bits and actual
ratio bits are at bits [23:16]. The current processing for level 1 and
level 2 is wrong as there is no shift done to get actual ratio.

Fixes: 6a35fc2d (cpufreq: intel_pstate: get P1 from TAR when available)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 94862a62

drivers/cpufreq/intel_pstate.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -813,6 +813,11 @@ static int core_get_max_pstate(void)
		if (err)
		goto skip_tar;

		/* For level 1 and 2, bits[23:16] contain the ratio */
		if (tdp_ctrl)
		tdp_ratio >>= 16;

		tdp_ratio &= 0xff; /* ratios are only 8 bits long */
		if (tdp_ratio - 1 == tar) {
		max_pstate = tar;
		pr_debug("max_pstate=TAC %x\n", max_pstate);