Re: [PATCH] arm64: dts: hikey: Give wifi some time after power-on

From: Jan Kiszka
Date: Tue Jan 15 2019 - 03:10:48 EST


On 06.01.19 10:53, Jan Kiszka wrote:
On 03.01.19 22:32, Ulf Hansson wrote:
On Wed, 2 Jan 2019 at 23:21, John Stultz <john.stultz@xxxxxxxxxx> 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@xxxxxx> wrote:

From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

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!


Any news on this regression?

Jan