linux-kernel - Re: [PATCH v3] PCI: Detect and trust built-in Thunderbolt chips

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Message-ID: <e5ca4c50-f64b-4a1a-82bb-f87a43020f7e@amd.com>
Date: Fri, 23 Aug 2024 10:36:34 -0500
From: Mario Limonciello <mario.limonciello@....com>
To: Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc: Esther Shimanovich <eshimanovich@...omium.org>,
 Bjorn Helgaas <bhelgaas@...gle.com>, Rajat Jain <rajatja@...gle.com>,
 "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>, iommu@...ts.linux.dev,
 Lukas Wunner <lukas@...ner.de>, linux-pci@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] PCI: Detect and trust built-in Thunderbolt chips

On 8/23/2024 00:01, Mika Westerberg wrote:
> Hi,
> 
> On Thu, Aug 22, 2024 at 10:56:44AM -0500, Mario Limonciello wrote:
>>>> Here's the snippet from the kernel log with the patch in place.  You can see
>>>> it flagged 00:02.0 as untrusted and removable, but it definitely isn't.
>>>
>>> Is it marked as ExternalFacingPort in the ACPI tables?
>>
>> No; it doesn't have an ACPI companion device.
> 
> Hm, how can it pass this then?
> 
> static bool pcie_is_tunneled(struct pci_dev *pdev)
> {
> 	...
> 	/* Internal PCIe devices are not tunneled. */
> 	if (!root->external_facing)
> 		return false;
> 	...
> 
> Would you mind adding some debug statements there so we can see
> (hopefully) what goes wrong?
> 
> The intention is that pcie_switch_directly_under() is only called on
> Intel pre-USB4 discrete controllers (well and Maple Ridge as that's
> still using the Connection Manager firmware).

Ah, I made a mistake on my system and was mixing up 00:02.0 and 02:00.0!

Everything is working as intended, thanks.

Reviewed-by: Mario Limonciello <mario.limonciello@....com>
Tested-by: Mario Limonciello <mario.limonciello@....com>