[PATCH v2] arm64: dts: hikey: Give wifi some time after power-on

[Jan Kiszka]

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 would already be happy with 1 ms. Still, we use the safer 10 ms,
like on the Ultra96.

Fixes: ea452678734e ("arm64: dts: hikey: Fix WiFi support")
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---

Changes in v2:
 - set delay to 10 ms
 - updated changelog

Who will take care of updating also the Hikey firmware dts with this
change?

 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 610235028cc7..ba946543dd0a 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 = <10>;
 		power-off-delay-us = <10>;
 	};

--
2.16.4