Re: [PATCH] drm/xe: Only probe stolen memory when display support is enabled.

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

On 2/27/2025 7:05 AM, Matthew Auld wrote:
> On 27/02/2025 14:55, Maarten Lankhorst wrote:
>> Without display, there is no need for display stolen memory.
>>
>> Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
>
> There is also xe_gsc_init_post_hwconfig() which looks to use stolen, 
> and I don't think that is dependent on display. But maybe that gsc 
> stuff doesn't have to use stolen? Daniele, any idea here?

The GSC allocation does have to use stolen, at least on some platforms. 
I think the requirement might be gone from recent platforms (PTL 
onwards) because the FW is now being copied to WOPCM instead, but I am 
not 100% sure. I didn't confirm this because we still need to keep using 
stolen for older platforms and it was just easier to keep using stolen 
everywhere; if you think there is value in changing this for newer 
platforms I can check with the GSC team and confirm.

Daniele

>
>> ---
>>   drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c 
>> b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> index d9c9d2547aadf..2e60d5346ec43 100644
>> --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> @@ -218,7 +218,7 @@ int xe_ttm_stolen_mgr_init(struct xe_device *xe)
>>       if (!mgr)
>>           return -ENOMEM;
>>   -    if (IS_SRIOV_VF(xe))
>> +    if (!xe->info.probe_display)
>>           stolen_size = 0;
>>       else if (IS_DGFX(xe))
>>           stolen_size = detect_bar2_dgfx(xe, mgr);
>