Re: [PATCH i-g-t v4 2/2] tests/intel/xe_pm: Add a check for power management capability

["Bernatowicz, Marcin" <marcin.bernatowicz@linux.intel.com>]

On 3/19/2025 9:05 AM, Poosa, Karthik wrote:
> 
> On 18-03-2025 20:31, Jakub Kolakowski wrote:
>> Add a check for power management capability of device tested in tests
>> related to D3 states. Currently if test is started on configuration
>> that does not support the PM capability it doesn't skip, instead
>> depending on test it may fail, abort or timeout.
>> With this change test will skip with a clear message why it did.
>>
>> Cc: Adam Miszczak<adam.miszczak@linux.intel.com>
>> Cc: Lukasz Laguna<lukasz.laguna@intel.com>
>> Cc: Marcin Bernatowicz<marcin.bernatowicz@linux.intel.com>
>> Signed-off-by: Jakub Kolakowski<jakub1.kolakowski@intel.com>
>> ---
>>   tests/intel/xe_pm.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
>> index c2026474d..70f0613fb 100644
>> --- a/tests/intel/xe_pm.c
>> +++ b/tests/intel/xe_pm.c
>> @@ -146,6 +146,9 @@ static void vram_d3cold_threshold_restore(int sig)
>>   static bool setup_d3(device_t device, enum igt_acpi_d_state state)
>>   {
>> +    igt_require_f(igt_has_pci_pm_capability(device.pci_xe),
>> +              "PCI power management capability not found\n");
> 
> Hi Jakub,
> 
> As per PCIe Base spec, all PCI Express Functions are required to support 
> PCI Power Management Capability.
> 
> Only legacy PCI devices wouldn't have it.
> 
> Can you share details of failures without this capability.
> 
> All Xe supported GPUs are PCIe complaint, this check may not be needed 
> at all.

This happens for runs with Virtual Function (VF) passed to Virtual 
Machine (VM).

"9.6 SR-IOV Power Management
This section defines the PCI Express SR-IOV power management 
capabilities and protocols.
The Power Management Capability is required for PFs as described in 
Chapter 5 .
For VFs, the Power Management Capability is optional."

--
marcin

> 
> 
>> +
>>       dpms_on_off(device, DRM_MODE_DPMS_OFF);
>>       /*