From:   Jan Kiszka <jan.kiszka@web.de>
Subject: [PATCH v2] arm64: dts: zcu100-revC: Give wifi some time after
 power-on
To:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Wei Xu <xuwei5@hisilicon.com>
Cc:     Ryan Grachek <ryan@edited.us>,
        John Stultz <john.stultz@linaro.org>,
        linux-wireless@vger.kernel.org, "Reizer, Eyal" <eyalr@ti.com>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Kalle Valo <kvalo@codeaurora.org>,
        Tony Lindgren <tony@atomide.com>,
        Michal Simek <michal.simek@xilinx.com>
Message-ID: <efc793c8-da17-e267-851e-f08f097843ee@web.de>
Date:   Thu, 24 Jan 2019 09:28:59 +0100
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From: Jan Kiszka <jan.kiszka@siemens.com>

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>
=2D--

Changes in v2:
 - fix changelog

 arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-zcu100-revC.dts b/arch/arm6=
4/boot/dts/xilinx/zynqmp-zcu100-revC.dts
index 13a0a028df98..e5699d0d91e4 100644
=2D-- 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 =3D "mmc-pwrseq-simple";
 		reset-gpios =3D <&gpio 7 GPIO_ACTIVE_LOW>; /* WIFI_EN */
+		post-power-on-delay-ms =3D <10>;
 	};
 };

=2D-
2.16.4