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SubjectRe: [PATCH] arm64: dts: hikey: Give wifi some time after power-on
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On 03.01.19 22:32, Ulf Hansson wrote:
> On Wed, 2 Jan 2019 at 23:21, John Stultz <john.stultz@linaro.org> wrote:
>>
>> Adding a few folks to cc from the thread here:
>> https://patchwork.kernel.org/patch/10734021/
>>
>> As this sounds like a very similar issue.
>> thanks
>> -john
>
> John, thanks for looping me in.
>
>>
>> On Sun, Dec 30, 2018 at 3:38 AM Jan Kiszka <jan.kiszka@web.de> wrote:
>>>
>>> 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.
>
> According to the discussions we had so far, this doesn't sound like
> the correct solution.
>
> I am intending to post patch soon, however, I am not sure exactly what
> solution to pick yet. I will keep you on cc - and of course I
> appreciate if you could help to test.
>

FWIW, the Ultra96 is also affected. Here I worked around it by using a 10 ms
power-on delay. The original workaround from the other thread did not help.
Looking forward to the proper fix now!

Jan

> Kind regards
> Uffe
>
>>>
>>> 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

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