[PATCH 4.20 155/171] arm64: dts: hikey: Give wifi some time after power-on

Greg Kroah-Hartman
2019-03-12T17:58:17Z

From: Jan Kiszka <jan.kiszka@siemens.com>

commit 83b944174ad79825ae84a47af1a0354485b24602 upstream.

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")
Cc: <stable@vger.kernel.org> #4.12+
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- 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>;
};