arm64: dts: zcu100-revC: Give wifi some time after power-on

Somewhere along recent changes to power control of the wl1831, power-on
became very unreliable on the Ultra96, 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,
Ultra96 is already happy with 10 ms.

Fixes: 5869ba0653b9 ("arm64: zynqmp: Add support for Xilinx zcu100-revC")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts b/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
index 13a0a028df985837522445d2b998ab7953abca95..e5699d0d91e45df9809a6875a9ac2da7942a9228 100644 (file)
--- a/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
+++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts
@@ -101,6 +101,7 @@
        sdio_pwrseq: sdio-pwrseq {
                compatible = "mmc-pwrseq-simple";
                reset-gpios = <&gpio 7 GPIO_ACTIVE_LOW>; /* WIFI_EN */
+               post-power-on-delay-ms = <10>;
        };
 };