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Date:   Tue, 6 Sep 2022 18:22:27 +0300
From:   Mika Westerberg <mika.westerberg@linux.intel.com>
To:     Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc:     andreas.noever@gmail.com, michael.jamet@intel.com,
        YehezkelShB@gmail.com, sanju.mehta@amd.com,
        mario.limonciello@amd.com, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] thunderbolt: Resume PCIe bridges after switch is found
 on AMD USB4 controller
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On Tue, Sep 06, 2022 at 05:59:49PM +0300, Mika Westerberg wrote:
> This reminded me that in Intel hardware there is an ACPI power resource that is
> shared between related devices. IIRC there is _PR0() method under the root
> port, xHCI and the TBT NHI that returns the same power resource. Now, when the
> power resource is turned on for any of the devices the kernel wakes up the rest
> too to make sure they get properly re-initialized if they went into
> D0unitialized or something like that. The commit that added this is
> 4533771c1e53 ("ACPI / PM: Introduce concept of a _PR0 dependent device").

Probably has nothing to do with this actually.