[Ksummit-2013-discuss] ARM topic: Is DT on ARM the solution, or is there something better?

[Rob Herring]

On Wed, Oct 23, 2013 at 6:41 AM, Peter Maydell <peter.maydell at linaro.org> wrote:
> On 22 October 2013 22:44, Matt Sealey <neko at bakuhatsu.net> wrote:
>> Any driver that fails probing for an optional property is
>> broken and needs fixing.
>
> I agree, but I note that by this rule all the primecell peripheral
> drivers are broken, because the binding docs say that the
> "clocks" and "clock-names" properties are optional but if you
> omit them from the dt node then the kernel refuses to even
> call the driver's probe code. (This is specifically irritating for
> QEMU because it means we have to create a dummy clock
> node in our device tree just to placate the kernel sufficiently
> that we can get it to talk to a PL011 UART model.)

I agree this is broken. The amba bus code should allow for
non-existent clocks. I thought it did, but maybe this changed or my
memory is just broken as well.

Rob