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From: Philippe Longepe <philippe.longepe@linux.intel.com>
To: linux-pm@vger.kernel.org
Cc: srinivas.pandruvada@linux.intel.com, rafael@kernel.org
Subject: [PATCH V6 1/4] intel_pstate: Remove extra conversions in pid calculation
Date: Tue,  8 Mar 2016 10:31:15 +0100	[thread overview]
Message-ID: <1457429481-13283-4-git-send-email-philippe.longepe@linux.intel.com> (raw)
In-Reply-To: <1457429481-13283-1-git-send-email-philippe.longepe@linux.intel.com>

pid->setpoint and pid->deadband can be initialized in fixed point, so we
can avoid the int_tofp in pid_calc.

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
---
 drivers/cpufreq/intel_pstate.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index eb0aef0..114e4e0 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -198,8 +198,8 @@ static struct perf_limits *limits = &powersave_limits;
 
 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 			     int deadband, int integral) {
-	pid->setpoint = setpoint;
-	pid->deadband  = deadband;
+	pid->setpoint = int_tofp(setpoint);
+	pid->deadband  = int_tofp(deadband);
 	pid->integral  = int_tofp(integral);
 	pid->last_err  = int_tofp(setpoint) - int_tofp(busy);
 }
@@ -225,9 +225,9 @@ static signed int pid_calc(struct _pid *pid, int32_t busy)
 	int32_t pterm, dterm, fp_error;
 	int32_t integral_limit;
 
-	fp_error = int_tofp(pid->setpoint) - busy;
+	fp_error = pid->setpoint - busy;
 
-	if (abs(fp_error) <= int_tofp(pid->deadband))
+	if (abs(fp_error) <= pid->deadband)
 		return 0;
 
 	pterm = mul_fp(pid->p_gain, fp_error);
-- 
1.9.1


  parent reply	other threads:[~2016-03-08  9:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-08  9:31 [PATCH V6 0/4] Reduce the intel_pstate timer overhead Philippe Longepe
2016-03-08  9:31 ` Philippe Longepe
2016-03-08  9:31 ` [PATCH V6 1/4] intel_pstate: Remove extra conversions in pid calculation Philippe Longepe
2016-03-08  9:31 ` Philippe Longepe [this message]
2016-03-08  9:31 ` [PATCH V6 2/4] intel_pstate: Optimize calculation for max/min_perf_adj Philippe Longepe
2016-03-08  9:31 ` Philippe Longepe
2016-03-08  9:31 ` [PATCH V6 3/4] intel_pstate: Move the intel_pstate_calc_busy into get_target_pstate_use_performance Philippe Longepe
2016-03-08  9:31 ` Philippe Longepe
2016-03-08  9:31 ` [PATCH V6 4/4] intel_pstate: Remove the freq calculation from the intel_pstate_calc_busy function Philippe Longepe
2016-03-08  9:31 ` Philippe Longepe
2016-03-10 23:19 ` [PATCH V6 0/4] Reduce the intel_pstate timer overhead Rafael J. Wysocki

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