Re: [PATCH v2 1/8] driver core: make deferring probe after init optional

From: Frank Rowand
Date: Tue May 29 2018 - 01:12:22 EST


On 05/24/18 11:18, Mark Brown wrote:
> On Thu, May 24, 2018 at 12:50:17PM -0500, Rob Herring wrote:
>
>> Subsystems or drivers may opt-in to this behavior by calling
>> driver_deferred_probe_check_init_done() instead of just returning
>> -EPROBE_DEFER. They may use additional information from DT or kernel's
>> config to decide whether to continue to defer probe or not.
>
> Should userspace have some involvement in this decision? It knows if
> it's got any intention of loading modules for example. Kernel config
> checks might be good enough, though it's going to be a pain to work out
> if the relevant driver is built as a module for example.
>

A parallel issue is that loading an overlay could provide the resource
that will allow the deferred probe to complete. (That is, once we
finish implementing the run time overlays feature.)

-Frank