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

From: Greg Kroah-Hartman
Date: Thu Jan 07 2021 - 15:05:16 EST


On Thu, Dec 17, 2020 at 07:16:58PM -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).
>
> Greg/Rafael,
>
> Can we get this pulled into 5.11-rc1 or -rc2 soon please? I expect to
> see some issues due to device drivers that aren't following best
> practices (they don't expose the device to driver core). Want to
> identify those early on and try to have them fixed before 5.11 release.
> See [1] for an example of such a case.

Now queued up in my tree, will show up in linux-next in a few days,
let's see what breaks! :)

And it is scheduled for 5.12-rc1, not 5.11, sorry.

thanks,

greg k-h