Re: [PATCH v2 3/4] ARM: dts: exynos5250: Fold common ChromeOS parts into Snow

Doug Anderson
2014-07-29T15:27:18Z

Andreas,

On Tue, Jul 29, 2014 at 6:00 AM, Andreas Färber <afaerber@suse.de> wrote:
> Hi Javier and Doug,
>
> Am 25.07.2014 19:02, schrieb Javier Martinez Canillas:
>> On Fri, Jul 25, 2014 at 6:43 PM, Doug Anderson <dianders@chromium.org> wrote:
>>> On Fri, Jul 25, 2014 at 9:35 AM, Javier Martinez Canillas
>>> <javier@dowhile0.org> wrote:
>>>> Hello Andreas,
>>>>
>>>> On Fri, Jul 18, 2014 at 7:20 PM, Andreas Färber <afaerber@suse.de> wrote:
>>>>>
>>>>> + memory {
>>>>> + reg = <0x40000000 0x80000000>;
>>>>> + };
>>>>> +
>>>>> + chosen {
>>>>> + };
>>>>> +
>>>>
>>>> Is there a reason for an empty chosen node? Same for the Spring DTS.
>>>
>>> I know that the bootloader (U-Boot) fills this in. I'd have to double
>>> check how the bootloader handles the node not being there to begin
>>> with.
>>
>> Yes, U-Boot fills this but if the node does not exist in the FDT, it
>> creates one. Take a look at fdt_chosen() in common/fdt_support.c [0].
>>
>> So I think it's better to just remove it since is empty.
>
> Hm, in different context it was stated that device trees shouldn't rely
> on bootloader behavior (for a /memory node on Zynq we ended up
> specifying the size cell with the real value despite U-Boot overriding
> it to a lesser value).
>
> Can we instead settle on filling this node with defaults? :)
> bootargs = "console=tty1"; would be my choice for Spring. Would that be
> applicable for Snow as well?

Personally I think that there's not a lot of use for including
bootargs. Every single person will need different bootargs since
everyone will have a different boot source (eMMC partitioin 0, eMMC
partition3, SD card, USB, etc). You have to rely on the bootloader
for _something_.

> Not sure how to specify that via linux,stdout-path property.
>
> I believe this would be a follow-up patch either way.

Right

> Since there's at least two series out there trying to fiddle with
> -cros-common.dtsi, including one that drops the slot sub-node of the MMC
> and one that adds CPU power supply, it would be nice if we can get the
> -cros-common parts sorted out and applied. Can you ack/review 1-2?
> Should I squash them in a v3?

Yeah, it will be a fight to see who gets landed first... :-P

I was thinking you were going to spin the patches and I'd do another
batch of review, but I think I can mark the first two as Reveiwed-by
if it's helpful to you. Let me do one more double-check when I get to
my desk.

-Doug