[SRU][Artful][Bionic][PATCH 1/1] cpufreq: powernv: Dont assume distinct pstate values for nominal and pmin

Joseph Salisbury joseph.salisbury at canonical.com
Fri Feb 16 16:30:49 UTC 2018

From: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1746174

Some OpenPOWER boxes can have same pstate values for nominal and
pmin pstates. In these boxes the current code will not initialize
'powernv_pstate_info.min' variable and result in erroneous CPU
frequency reporting. This patch fixes this problem.

Fixes: 09ca4c9b5958 (cpufreq: powernv: Replacing pstate_id with frequency table index)
Reported-by: Alvin Wang <wangat at tw.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar at linaro.org>
Cc: 4.8+ <stable at vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
(cherry picked from commit 3fa4680b860bf48b437d6a2c039789c4abe202ae)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
 drivers/cpufreq/powernv-cpufreq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 3ff5160..7e1e5bb 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -287,9 +287,9 @@ static int init_powernv_pstates(void)
 		if (id == pstate_max)
 			powernv_pstate_info.max = i;
-		else if (id == pstate_nominal)
+		if (id == pstate_nominal)
 			powernv_pstate_info.nominal = i;
-		else if (id == pstate_min)
+		if (id == pstate_min)
 			powernv_pstate_info.min = i;
 		if (powernv_pstate_info.wof_enabled && id == pstate_turbo) {

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