Re: [PATCH 4/4] arm64: DTS: allwinner: a64: enable ANX6345 bridge on Teres-I

From: Vasily Khoruzhick
Date: Thu May 16 2019 - 14:28:33 EST


On Thu, May 16, 2019 at 9:49 AM Torsten Duwe <duwe@xxxxxx> wrote:
>
> On Thu, May 16, 2019 at 09:06:41AM -0700, Vasily Khoruzhick wrote:
> >
> > Driver can talk to the panel over AUX channel only after t1+t3, t1 is
> > up to 10ms, t3 is up to 200ms.
>
> This is after power-on. The boot loader needs to deal with this.

Actually panel driver has to deal with it and not bootloader.

> > It works with older version of driver
> > that keeps panel always on because it takes a while between driver
> > probe and pipeline start.
>
> No lid switch, no USB, no WiFi, no MMC. If you disable DCDC1 you'll
> run out of wakeup-sources ;-) IOW: I see no practical way any OS
> driver can switch this panel voltage off and survive...

Ouch, looks like someone made a huge mistake in HW design?

> > All in all - you don't need panel timings since there's EDID but you
> > still need panel delays. Anyway, it's up to you and maintainers.
>
> Let's give it a try.
>
> Torsten
>