Re: [1/3] drm/xe: Toggle the D3Cold enable flag at runtime resume

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 10/16/2026 11:23 AM, Poosa, Karthik wrote:
>
> On 15-10-2026 22:24, Vinay Belgaumkar wrote:
>> We enable this flag during runtime suspend,
> i think there should be Fixes tag for this.
>
> Fixes: f026520367be ("drm/xe: Only set PCI d3cold_allowed when we are 
> really allowing.")
ok.
>
>> need to set it back to
>> false early during resume to prevent any race with pci driver.
> What is race that seen without this ?

While D0 is being programmed in xe_pci_runtime_resume(), pci driver's 
internal auto suspend timer could expire and, since this d3cold flag is 
still true, pci driver could try to put vsp into D3. This is probably 
why we toggle this flag as the very first thing in the S3 resume 
function xe_pci_resume().

Thanks,

Vinay.

>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_pci.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
>> index 57c6f778ca24..2269e51868c1 100644
>> --- a/drivers/gpu/drm/xe/xe_pci.c
>> +++ b/drivers/gpu/drm/xe/xe_pci.c
>> @@ -1450,6 +1450,9 @@ static int xe_pci_runtime_resume(struct device 
>> *dev)
>>       struct xe_device *xe = pdev_to_xe_device(pdev);
>>       int err;
>>   +    if (xe->d3cold.allowed)
>> +        d3cold_toggle(pdev, D3COLD_DISABLE);
>> +
>>       err = pci_set_power_state(pdev, PCI_D0);
>>       if (err)
>>           return err;