Nouveau - Jul 2025 - [PATCH v6 00/24] nova-core: run FWSEC-FRTS to perform first stage of GSP initialization

On Tue Jun 24, 2025 at 6:01 AM JST, Danilo Krummrich
wrote:
> There's one thing that would be nice to fix subsequently, which is
properly
> resetting the GPU. Currently, it needs a power cycle to be able to probe
> successfully after unbinding the driver.
Yes, what I usually do is the following after unloading Nova:

    echo 1 | sudo tee /sys/bus/pci/devices/0000:01:00.0/reset

and this allows it to probe again. Maybe we want to add some equivalent
programmatically in the driver probe function?

On 6/23/25 7:56 PM, Alexandre Courbot wrote:
> On Tue Jun 24, 2025 at 6:01 AM JST, Danilo Krummrich wrote:
>> There's one thing that would be nice to fix subsequently, which is
properly
>> resetting the GPU. Currently, it needs a power cycle to be able to
probe
>> successfully after unbinding the driver.
> 
> Yes, what I usually do is the following after unloading Nova:
> 
>     echo 1 | sudo tee /sys/bus/pci/devices/0000:01:00.0/reset
> 
> and this allows it to probe again. Maybe we want to add some equivalent
> programmatically in the driver probe function?
At this point, we are only getting things up to a certain very early
stage. And so we have to reset like this in order to try again.

But I'm not sure that will be the case, once we have more code in
place to go further.

So maybe hold off on this for a few weeks or so?

thanks,
-- 
John Hubbard

On 6/24/25 4:56 AM, Alexandre Courbot wrote:
> On Tue Jun 24, 2025 at 6:01 AM JST, Danilo Krummrich wrote:
>> There's one thing that would be nice to fix subsequently, which is
properly
>> resetting the GPU. Currently, it needs a power cycle to be able to
probe
>> successfully after unbinding the driver.
> 
> Yes, what I usually do is the following after unloading Nova:
> 
>      echo 1 | sudo tee /sys/bus/pci/devices/0000:01:00.0/reset
> 
> and this allows it to probe again. Maybe we want to add some equivalent
> programmatically in the driver probe function?
Probably -- how are things implemented on the GPU side of things? Is the GPU
firmware surviving a FLR?

On Tue Jul 1, 2025 at 12:43 AM JST, Danilo Krummrich
wrote:
> On 6/24/25 4:56 AM, Alexandre Courbot wrote:
>> On Tue Jun 24, 2025 at 6:01 AM JST, Danilo Krummrich wrote:
>>> There's one thing that would be nice to fix subsequently, which
is properly
>>> resetting the GPU. Currently, it needs a power cycle to be able to
probe
>>> successfully after unbinding the driver.
>> 
>> Yes, what I usually do is the following after unloading Nova:
>> 
>>      echo 1 | sudo tee /sys/bus/pci/devices/0000:01:00.0/reset
>> 
>> and this allows it to probe again. Maybe we want to add some equivalent
>> programmatically in the driver probe function?
>
> Probably -- how are things implemented on the GPU side of things? Is the
GPU
> firmware surviving a FLR?
After a FLR all firmware is cleared and the WPR2 region is wiped,
meaning GPU initialization has to be done again from the very beginning.