From 1a8293336815823c8791f6d50389dae38d91ba62 Mon Sep 17 00:00:00 2001 From: Merlijn Wajer Date: Fri, 13 Apr 2018 22:30:37 +0200 Subject: [PATCH] When we set or clear a pmic_bus bit, we do a read-modify-write operation. We waste some time however, by writing back the exact same value that was already set in the chip. Let us thus only configure the chip if the data is different. --- arch/arm/mach-sunxi/pmic_bus.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm/mach-sunxi/pmic_bus.c b/arch/arm/mach-sunxi/pmic_bus.c index f917c3e..1f113c7 100644 --- a/arch/arm/mach-sunxi/pmic_bus.c +++ b/arch/arm/mach-sunxi/pmic_bus.c @@ -102,6 +102,9 @@ int pmic_bus_setbits(u8 reg, u8 bits) if (ret) return ret; + if (val & bits) + return 0; + val |= bits; return pmic_bus_write(reg, val); } @@ -115,6 +118,9 @@ int pmic_bus_clrbits(u8 reg, u8 bits) if (ret) return ret; + if (!(val & bits)) + return 0; + val &= ~bits; return pmic_bus_write(reg, val); }