Re: [PATCH 2/2] thunderbolt: Initialize after IOMMUs

From: Lukas Wunner
Date: Thu Sep 06 2018 - 07:00:55 EST


On Thu, Sep 06, 2018 at 01:36:02PM +0300, Mika Westerberg wrote:
> On Thu, Sep 06, 2018 at 10:13:37AM +0200, Lukas Wunner wrote:
> > So with this patch, you rely on the linker ordering nhi_init() after
> > ir_dev_scope_init(), however to the best of my knowledge the link
> > order is not guaranteed.
>
> What says that?

Within the same initcall level, the ordering is determined by the Makefile
AFAIK. Someone changes the Makefile, your dependency scheme falls apart.


> > Looking at commit acb40d841257, which started this, I'm wondering
> > why you did not simply export tbnet_init() and call it from the
> > thunderbolt driver after the property stuff has been fully set up?
> > After all, thunderbolt-net is useless without thunderbolt or am I
> > missing something? Then you could revert back to module_init().
>
> The same reason you don't call PCI driver functions from PCI core. It
> makes absolutely zero sense.
>
> Thunderbolt is bus and provides driver API to drivers. We hopefully are
> getting other service drivers (say SCSI over TBT) that are going to be
> use the same interfaces.

Then add a blocking notifier chain into which these service drivers can
hook. Other buses have that as well.

Thanks,

Lukas