linux-kernel - Re: [PATCH] thunderbolt: Resume PCIe bridges after switch is found on AMD USB4 controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Yxdls5XlZ0EBGfON@black.fi.intel.com>
Date:   Tue, 6 Sep 2022 18:22:27 +0300
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     Kai-Heng Feng <kai.heng.feng@...onical.com>
Cc:     andreas.noever@...il.com, michael.jamet@...el.com,
        YehezkelShB@...il.com, sanju.mehta@....com,
        mario.limonciello@....com, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] thunderbolt: Resume PCIe bridges after switch is found
 on AMD USB4 controller

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.