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* [PATCH] arm64: dts: hikey: Give wifi some time after power-on
@ 2018-12-30 11:38 Jan Kiszka
  2019-01-02 22:21 ` John Stultz
  0 siblings, 1 reply; 6+ messages in thread
From: Jan Kiszka @ 2018-12-30 11:38 UTC (permalink / raw)
  To: Linux Kernel Mailing List, linux-arm-kernel, Wei Xu
  Cc: Ryan Grachek, John Stultz, linux-wireless, Reizer, Eyal,
	Valentin Schneider

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

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@siemens.com>
---

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

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-01-15  8:13 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-12-30 11:38 [PATCH] arm64: dts: hikey: Give wifi some time after power-on Jan Kiszka
2019-01-02 22:21 ` John Stultz
2019-01-03 21:32   ` Ulf Hansson
2019-01-06  9:53     ` Jan Kiszka
2019-01-15  8:10       ` Jan Kiszka
2019-01-15  8:13         ` Ulf Hansson

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