[PATCH 2/6] hwmon: amd_energy: optimize accumulation interval

[Naveen Krishna Chatradhi <nchatrad@amd.com>]

On a system with course grain resolution of energy unit (milli J) the
accumulation thread can be executed less frequently than on the system
with fine grain resolution(micro J).

This patch sets the accumulation thread interval to an optimum value
calculated based on the (energy unit) resolution supported by the
hardware (assuming a peak wattage of 240W).

Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
---
 drivers/hwmon/amd_energy.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/amd_energy.c b/drivers/hwmon/amd_energy.c
index 9580a16185b8..f0a13d6cc419 100644
--- a/drivers/hwmon/amd_energy.c
+++ b/drivers/hwmon/amd_energy.c
@@ -48,6 +48,7 @@ struct amd_energy_data {
 	struct sensor_accumulator *accums;
 	/* Energy Status Units */
 	u64 energy_units;
+	unsigned int timeout;
 	int nr_cpus;
 	int nr_socks;
 	int core_id;
@@ -215,6 +216,7 @@ static umode_t amd_energy_is_visible(const void *_data,
 static int energy_accumulator(void *p)
 {
 	struct amd_energy_data *data = (struct amd_energy_data *)p;
+	unsigned int timeout = data->timeout;
 
 	while (!kthread_should_stop()) {
 		/*
@@ -234,7 +236,7 @@ static int energy_accumulator(void *p)
 		 *
 		 * let us accumulate for every 100secs
 		 */
-		schedule_timeout(msecs_to_jiffies(100000));
+		schedule_timeout(msecs_to_jiffies(timeout));
 	}
 	return 0;
 }
@@ -331,6 +333,14 @@ static int amd_energy_probe(struct platform_device *pdev)
 	if (IS_ERR(hwmon_dev))
 		return PTR_ERR(hwmon_dev);
 
+	/* Once in 3 minutes for a resolution of 1/2*16 */
+	if (data->energy_units == 0x10)
+		data->timeout = 3 * 60;
+
+	/* Once in 3 days for a resolution of 1/2^6 */
+	if (data->energy_units == 0x6)
+		data->timeout = 3 * 24 * 60 * 60;
+
 	data->wrap_accumulate = kthread_run(energy_accumulator, data,
 					    "%s", dev_name(hwmon_dev));
 	if (IS_ERR(data->wrap_accumulate))
-- 
2.26.2