From c970e8954f084b543d241fd96c0377988d8d4971 Mon Sep 17 00:00:00 2001 From: Olliver Schinagl Date: Wed, 21 Nov 2018 20:05:26 +0200 Subject: [PATCH] sunxi: pmic_bus: Decrease boot time by not writing duplicate data When we clear a pmic_bus bit, we do a read-modify-write operation. We waste some time however, by writing back the exact samea value that was already set in the chip. Let us thus only do the write in case data was changed. Signed-off-by: Olliver Schinagl Signed-off-by: Priit Laes Acked-by: Maxime Ripard --- 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 5d91d7e2c1..dea42de833 100644 --- a/arch/arm/mach-sunxi/pmic_bus.c +++ b/arch/arm/mach-sunxi/pmic_bus.c @@ -101,6 +101,9 @@ int pmic_bus_setbits(u8 reg, u8 bits) if (ret) return ret; + if ((val & bits) == bits) + return 0; + val |= bits; return pmic_bus_write(reg, val); } @@ -114,6 +117,9 @@ 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); } -- 2.39.5