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From:   =?UTF-8?B?SmFuIETEhWJyb8Wb?= <jsd@semihalf.com>
Date:   Mon, 16 Jan 2023 11:19:00 +0100
Message-ID: <CAOtMz3PG4nku-O7dh+1U_DA05HAmQboTqwUQkCkrXQLV9bFjPw@mail.gmail.com>
Subject: Re: [PATCH -next 1/2] i2c: designware: Switch from using MMIO access
 to SMN access
To:     Borislav Petkov <bp@alien8.de>
Cc:     "Limonciello, Mario" <mario.limonciello@amd.com>,
        Borislav Petkov <bp@suse.de>,
        Hans de Goede <hdegoede@redhat.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
        jarkko.nikula@linux.intel.com, wsa@kernel.org,
        rrangel@chromium.org, upstream@semihalf.com,
        Muralidhara M K <muralimk@amd.com>,
        Naveen Krishna Chatradhi <nchatrad@amd.com>,
        Yazen Ghannam <yazen.ghannam@amd.com>
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Hi Borislav,

> Make init_amd_nbs() arch_initcall_sync() so that it executes after PCI init.

I described earlier in this thread why such option is not working -
let me quote myself:

It's not enough for running init_amd_nbs() to have only
pci_arch_init() done. We need the pci bus to be created and registered
with all devices found on the bus. We are traversing through them and
trying to find northbridge VID/DID. Due to the above, we need to run
init_amd_nbs() only after acpi_scan_init() that is invoked from
acpi_init() which is registered as subsys_initcall. That's why the
trick with switching init_amd_nbs() to arch_initcall_sync will not
work.

We have a kind of chicken-and-egg problem here. Or is there something I missed?

I wonder if there is upstreamable option to control order of the
drivers' init by forcing link order?

Best Regards,
Jan