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From: Esther Shimanovich <eshimanovich@chromium.org>
Date: Thu, 18 Apr 2024 15:43:08 -0400
Message-ID: <CA+Y6NJF6+s5zUZeaWtagpMt8Qu0a1oE+3re3c6EsppH+ZsuMRQ@mail.gmail.com>
Subject: Re: [PATCH v4] PCI: Relabel JHL6540 on Lenovo X1 Carbon 7,8
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mario Limonciello <mario.limonciello@amd.com>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, 
	Lukas Wunner <lukas@wunner.de>, Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org, 
	linux-kernel@vger.kernel.org, Rajat Jain <rajatja@google.com>
Content-Type: text/plain; charset="UTF-8"

Thank you for your response! It is very much appreciated.

On the Tiger Lake device I was testing on, the usb4-host-interface
value is NOT listed in its ACPI.

I then decided to query the ACPI values collected from devices in my
office, to see if this issue is limited to my device.
Ice Lake - 4 devices, none had "usb4-host-interface"
Tiger Lake - 31 devices, none have "usb4-host-interface"
Alder Lake - 32 devices, I see that 15 of them have
"usb4-host-interface" in their ACPI
Raptor Lake - 1 device, does not have "usb4-host-interface"

It looks like only Alder Lake has usb4-host-interface  listed in its
ACPI for whatever reason.

It seems like I cannot use usb4-host-interface as a determinant
whether the CPU has Thunderbolt capabilities (thus not needing a
discrete Thunderbolt chip).
ExternalFacingPort is listed in devices that don't have CPUs with
Thunderbolts, so that can't be a determinant.

Am I missing something?