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Subject: Re: Where are bus passes with lower than default pass value called?
To: Jan Mazur <dingorth@gmail.com>, freebsd-new-bus@freebsd.org
References: <CADGEm4fs0P7yBgUqcqdBvNNOo2Y0=QP1QwOrvbLgfzhmJzrdrw@mail.gmail.com>
Cc: Wojciech Moczulski <womoczulski@gmail.com>
From: John Baldwin <jhb@FreeBSD.org>
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Date: Wed, 24 Oct 2018 10:31:48 -0700
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On 5/28/18 3:16 AM, Jan Mazur wrote:
> Here: http://bxr.su/FreeBSD/sys/kern/subr_bus.c#901
> bus_current_pass is set to BUS_PASS_ROOT.
> 
> AFAIK autoconfiguration starts here:
> http://bxr.su/FreeBSD/sys/mips/mips/autoconf.c#95 and later it
> calls BUS_NEW_PASS(root_bus) which calls bus_set_pass(BUS_PASS_DEFAULT).
> Why is it called with maximum possible bus pass level - BUS_PASS_DEFAULT?
> Where are bus passes with lower pass value called?

bus_set_pass() walks up from the current bus pass to the requested bus
pass stopping at each level that has a registered driver.  The intention
is that eventually we may want to insert SYSINITs in between some of
the passes in which case a SYSINIT would use bus_set_pass with a lower
level and then do some other work, but currently we don't have any of those,
so we are still just passing through all the levels in one SYSINIT.

-- 
John Baldwin