Re: [BUG] PCI/USB4: AMD Phoenix 1022:14ef runtime suspend prevents JHL9480 downstream enumeration

[Mario Limonciello <mario.limonciello@amd.com>]

+Alex K

On 9/21/26 00:04, Mika Westerberg wrote:
> Hi,
> 
> Adding AMD folks in case this is known issue.
> 
> On Sat, Sep 19, 2026 at 12:39:37PM +0000, Freeman Z wrote:
>> Hello,
>>
>> I am seeing a reproducible USB4/PCIe runtime-PM problem on an ASUS ROG
>> Flow X13 GV302XV (Ryzen 9 7940HS / Phoenix) with a Kensington SD5000T5
>> EQ Thunderbolt 5 dock connected to the laptop's USB4 host port.
>>
>> The failure is reproducible with the official Arch Linux Live ISO using
>> Arch's stock `linux` kernel:
>>
>>      7.2.2-arch1-1
>>
>> I have not yet tested a self-built kernel.org mainline/vanilla kernel.
>> I can test patches, or collect additional traces if requested.
> 
> Can you provide full dmesg with "thunderbolt.dyndbg=+p" in the kernel
> command line?
> 
> With the below steps (following your description):
> 
> 0. Drop all non-standard command line options except the above.
> 1. Boot the system up, nothing connected.
> 2. Once up let the TB and the related PCIe root ports enter D3cold (don't
>     run lspci it will wake them up but you can look at the runtime status that
>     they are all suspended).
> 3. Plug in the dock.
> 
> We should see in the dmesg the PME if it works as expected. If not then it
> may be that there is something wrong with the wakeup path.

There was something like this that was reported in the past, but it was 
a race condition of some sort.  It ended up being fixed by a non-obvious 
optimization (I forget the specific commit).

But it was definitely older than 7.2, so it sounds like it might have 
regressed again.