Re: [PATCH v4] PCI: Prevent power state transition of erroneous device

[Denis Benato <benato.denis96@gmail.com>]

On 5/21/25 19:06, Mario Limonciello wrote:
> On 5/21/25 08:39, Lukas Wunner wrote:
>> On Tue, May 20, 2025 at 07:22:04PM +0200, Denis Benato wrote:
>>> This is the very same exact kernel, minus the patch in question:
>>> https://pastebin.com/rwMYgG7C
>>>
>>> Both previous kernel and this one have CONFIG_PCI_DEBUG=y.
>>
>> This log excerpt shows that the ASMedia Thunderbolt controller
>> below the Intel Thunderbolt controller couldn't be enumerated
>> on boot:
>>
>> mag 20 18:42:20 denis-pc kernel: pci 0000:03:01.0: broken device, retraining non-functional downstream link at 2.5GT/s
>> mag 20 18:42:20 denis-pc kernel: pci 0000:03:01.0: retraining failed
>>
>> However, the Thunderbolt tunnel goes up and the devices are
>> enumerated 24 seconds later:
>>
>> mag 20 18:42:44 denis-pc kernel: pcieport 0000:03:01.0: pciehp: Slot(1-1): Card present
>> mag 20 18:42:44 denis-pc kernel: pcieport 0000:03:01.0: pciehp: Slot(1-1): Link Up
>>
>> Thanks,
>>
>> Lukas
>
> Are you suggesting that the training failure is why there was an error?
>
> If so maybe that should be cleared when it does eventually train.
Oftentimes the gpu is not initialized when I boot my laptop: in that dmesg I posted I detached it and re-plugged when I saw displays not lighting up.

Using the patch proposed here the gpu is always there, that's why you don't see the same in the two dmesg in that regard.

Also another reason I want this patch to work.