[PATCH] arm64: dts: hikey: Give wifi some time after power-on

From: Jan Kiszka
Date: Sun Dec 30 2018 - 06:38:54 EST


From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

Somewhere along recent changes to power control of the wl1835, power-on
became very unreliable on the hikey, failing like this:

wl1271_sdio: probe of mmc2:0001:1 failed with error -16
wl1271_sdio: probe of mmc2:0001:2 failed with error -16

After playing with some dt parameters and comparing to other users of
this chip, it turned out we need some power-on delay to make things
stable again. In contrast to those other users which define 200 ms, the
hikey is already very happy with 1 ms.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---

Tested with 4.19 and linus/master.

arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts b/arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts
index f4964bee6a1a..1e771bf201b9 100644
--- a/arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts
+++ b/arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts
@@ -118,6 +118,7 @@
reset-gpios = <&gpio0 5 GPIO_ACTIVE_LOW>;
clocks = <&pmic>;
clock-names = "ext_clock";
+ post-power-on-delay-ms = <1>;
power-off-delay-us = <10>;
};

--
2.16.4