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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2023-11-20 21:59:42 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2023-12-05 23:29:47 +0300
commit2719675fa8111a8d7a060133e1dd4797d20c9754 (patch)
tree050bcb899539b70cef7b30e323310a7ca63e4034 /drivers/cpufreq
parent33cc938e65a98f1d29d0a18403dbbee050dcad9a (diff)
downloadlinux-2719675fa8111a8d7a060133e1dd4797d20c9754.tar.xz
cpufreq: intel_pstate: Prioritize firmware-provided balance performance EPP
The platform firmware can provide a balance performance EPP value by enabling HWP and programming the EPP to the desired value. However, currently this only takes effect for processors listed in intel_epp_balance_perf[], so in order to enable a new processor model to utilize this mechanism, that table needs to be updated. It arguably should not be necessary to modify the kernel to work properly with every new generation of processors, though, and distributions that don't always ship the most recent kernels should be able to run reasonably well on new hardware without code changes. For this reason, move the check to avoid updating the EPP when the balance performance EPP is unmodified from the power-up default of 0x80 after the check that allows the firmware-provided balance performance EPP value to be retrieved. This will cause the code to always look for the firmware- provided value before consulting intel_epp_balance_perf[] and the handling of new hardware will not depend on whether or not that thable has been updated yet. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/intel_pstate.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index a534a1f7f1ee..dd6d23e389f1 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1692,13 +1692,6 @@ static void intel_pstate_update_epp_defaults(struct cpudata *cpudata)
cpudata->epp_default = intel_pstate_get_epp(cpudata, 0);
/*
- * If this CPU gen doesn't call for change in balance_perf
- * EPP return.
- */
- if (epp_values[EPP_INDEX_BALANCE_PERFORMANCE] == HWP_EPP_BALANCE_PERFORMANCE)
- return;
-
- /*
* If the EPP is set by firmware, which means that firmware enabled HWP
* - Is equal or less than 0x80 (default balance_perf EPP)
* - But less performance oriented than performance EPP
@@ -1711,6 +1704,13 @@ static void intel_pstate_update_epp_defaults(struct cpudata *cpudata)
}
/*
+ * If this CPU gen doesn't call for change in balance_perf
+ * EPP return.
+ */
+ if (epp_values[EPP_INDEX_BALANCE_PERFORMANCE] == HWP_EPP_BALANCE_PERFORMANCE)
+ return;
+
+ /*
* Use hard coded value per gen to update the balance_perf
* and default EPP.
*/