[PATCH v5 4/4] soc: samsung: exynos-asv: Update Energy Model after adjusting voltage

From: Lukasz Luba
Date: Wed Apr 03 2024 - 11:51:02 EST


When the voltage for OPPs is adjusted there is a need to also update
Energy Model framework. The EM data contains power values which depend
on voltage values. The EM structure is used for thermal (IPA governor)
and in scheduler task placement (EAS) so it should reflect the real HW
model as best as possible to operate properly.

Based on data on Exynos5422 ASV tables the maximum power difference might
be ~29%. An Odroid-XU4 (with a random sample SoC in this chip lottery)
showed power difference for some OPPs ~20%. Therefore, it's worth to
update the EM.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Signed-off-by: Lukasz Luba <lukasz.luba@xxxxxxx>
---
drivers/soc/samsung/exynos-asv.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/samsung/exynos-asv.c b/drivers/soc/samsung/exynos-asv.c
index d60af8acc3916..97006cc3b9461 100644
--- a/drivers/soc/samsung/exynos-asv.c
+++ b/drivers/soc/samsung/exynos-asv.c
@@ -11,6 +11,7 @@

#include <linux/cpu.h>
#include <linux/device.h>
+#include <linux/energy_model.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
@@ -97,9 +98,16 @@ static int exynos_asv_update_opps(struct exynos_asv *asv)
last_opp_table = opp_table;

ret = exynos_asv_update_cpu_opps(asv, cpu);
- if (ret < 0)
+ if (!ret) {
+ /*
+ * Update EM power values since OPP
+ * voltage values may have changed.
+ */
+ em_dev_update_chip_binning(cpu);
+ } else {
dev_err(asv->dev, "Couldn't udate OPPs for cpu%d\n",
cpuid);
+ }
}

dev_pm_opp_put_opp_table(opp_table);
--
2.25.1