Re: [PATCH v1 0/5] Solve postboot supplier cleanup and optimize probe ordering

From: Frank Rowand
Date: Fri May 24 2019 - 20:26:16 EST


On 5/24/19 2:53 PM, Saravana Kannan wrote:
> On Fri, May 24, 2019 at 10:49 AM Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>>
>> On 5/23/19 6:01 PM, Saravana Kannan wrote:

< snip >

>> Another flaw with this method is that existing device trees
>> will be broken after the kernel is modified, because existing
>> device trees do not have the depends-on property. This breaks
>> the devicetree compatibility rules.
>
> This is 100% not true with the current implementation. I actually
> tested this. This is fully backwards compatible. That's another reason
> for adding depends-on and going by just what it says. The existing
> bindings were never meant to describe only mandatory dependencies. So
> using them as such is what would break backwards compatibility.

Are you saying that an existing, already compiled, devicetree (an FDT)
can be used to boot a new kernel that has implemented this patch set?

The new kernel will boot with the existing FDT that does not have
any depends-on properties?

-Frank