[PATCH v4 20/22] driver core: Allow deferring probes until late init

[Tomeu Vizoso]

On 11 September 2015 at 14:17, Mark Brown <broonie at kernel.org> wrote:
> On Mon, Sep 07, 2015 at 02:23:45PM +0200, Tomeu Vizoso wrote:
>> Add a field to struct device that instructs the device-driver core to
>> defer the probe of this device until the late_initcall level.
>>
>> By letting all built-in drivers to register before starting to probe, we
>> can avoid any deferred probes by probing dependencies on demand.
>
> Is this not going to resut in massive churn as we go through and set
> this flag for a massive proportion of drivers?  Could we mitigate this
> by having a first pass at setting this per subsystem or something so
> that we get a good proportion of drivers with changes in core code?

I think this flag should be only set during the initial registration
of devices (eg. acpi_device_add, of_device_add, etc), as by delaying
the probe of those we are automatically delaying the probe of the
rest.

Regards,

Tomeu