Re: [PATCH] arm64: dts: exynos: Add minimal bootargs

[Krzysztof Kozlowski]

On Sat, Jul 04, 2020 at 12:19:40AM +0530, Alim Akhtar wrote:
> Adding Krzysztof's correct email address.
> Sorry about noise.
> 
> > -----Original Message-----
> > From: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > Sent: 03 July 2020 23:56
> > To: rzk@xxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> > samsung-soc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > robh+dt@xxxxxxxxxx; Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > Subject: [PATCH] arm64: dts: exynos: Add minimal bootargs
> > 
> > Add minimal bootargs to enable earlycon and console.
> > This really useful in case kernel has crashed early in boot process.
> > 
> > Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > ---
> >  arch/arm64/boot/dts/exynos/exynos7-espresso.dts | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/arch/arm64/boot/dts/exynos/exynos7-espresso.dts
> > b/arch/arm64/boot/dts/exynos/exynos7-espresso.dts
> > index 790f12ca8981..d7b42d5a3b2d 100644
> > --- a/arch/arm64/boot/dts/exynos/exynos7-espresso.dts
> > +++ b/arch/arm64/boot/dts/exynos/exynos7-espresso.dts
> > @@ -24,6 +24,7 @@
> > 
> >  	chosen {
> >  		stdout-path = &serial_2;
> > +		bootargs = "earlycon=exynos4210,0x14c30000
> > console=ttySAC0,115200n8";

Hi,

The console is already chosen by stdout-path and earlycon would use it
as well, so no need for the address. It should be just "earlycon" if you
want to enable it unconditionally.

Also, why did you use different serial for console?

However the question is, are you sure you want earlycon on every,
including successful boot? On most of the boards we do not enable by
default. If developer needs, he can choose it for example via U-Boot
"setenv opts earlycon".

However it's a development kit so it could be enabled on default...

Best regards,
Krzysztof

> >  	};
> > 
> >  	memory@40000000 {
> > 
> > base-commit: 9e50b94b3eb0d859a2586b5a40d7fd6e5afd9210
> > --
> > 2.17.1
> 
>