Re: [PATCH] serial: 8250_early: Add earlycon for BCM2835 aux uart

From: Lukas Wunner
Date: Wed Feb 12 2020 - 08:28:38 EST


On Mon, Feb 03, 2020 at 08:10:21PM +0100, Nicolas Saenz Julienne wrote:
> On Fri, 2020-01-31 at 16:24 +0100, Lukas Wunner wrote:
> > On Thu, Jan 30, 2020 at 05:11:55PM +0100, Nicolas Saenz Julienne wrote:
> > > BTW did you had the oportunity to have a go at the patch?
> >
> > I've just performed a quick test and it doesn't work for me.
> > If I add stdout-path = "serial1:115200n8"; to the chosen node,
> > I only get a regular console with this patch, not an earlycon.
>
> That's surprising, you're using u-boot isn't it? and the upstream device tree?

My apologies for the delay.

We boot the kernel directly from the Foundation's bootloader without
U-Boot as intermediary, and we use the downstream DT and kernel
(with RT & custom patches).

As far as I could see, the 8250_bcm2835aux UART wasn't even found
when the kernel searched for available earlycons. The compatible
string in the DT does match the one in Matthias' patch.

I notice that Greg has already applied the patch to tty/next.
I'm currently stretched a little thin but I'll debug this further
once the dust has settled here.

Thanks,

Lukas