Re: [PATCH v1 0/5] Enable fw_devlink=on by default

[Saravana Kannan]

On Wed, Jan 13, 2021 at 3:48 AM Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On 2021-01-13 11:44, Nicolas Saenz Julienne wrote:
> > On Thu, 2020-12-17 at 19:16 -0800, Saravana Kannan wrote:
> >> As discussed in LPC 2020, cyclic dependencies in firmware that
> >> couldn't
> >> be broken using logic was one of the last remaining reasons
> >> fw_devlink=on couldn't be set by default.
> >>
> >> This series changes fw_devlink so that when a cyclic dependency is
> >> found
> >> in firmware, the links between those devices fallback to permissive
> >> mode
> >> behavior. This way, the rest of the system still benefits from
> >> fw_devlink, but the ambiguous cases fallback to permissive mode.
> >>
> >> Setting fw_devlink=on by default brings a bunch of benefits
> >> (currently,
> >> only for systems with device tree firmware):
> >> * Significantly cuts down deferred probes.
> >> * Device probe is effectively attempted in graph order.
> >> * Makes it much easier to load drivers as modules without having to
> >>   worry about functional dependencies between modules (depmod is still
> >>   needed for symbol dependencies).
> >
> > FWIW I don't see any issues with this on Raspberry Pi 4 :).
>
> Keep bragging! ;-)
>

Yay! Thanks for confirming Nicolas.

-Saravana