Re: [PATCH 3/3] drm/xe/display: Do not allocate into stolen for new framebuffers.

[Matthew Auld <matthew.auld@intel.com>]

On 30/06/2026 14:55, Maarten Lankhorst wrote:
> Prefer to use system memory for global framebuffers, and reserve
> the space for FBC use only.
> 
> Now that multiple CRTC's can use FBC's, the simple heuristic
> of using less than half of stolen is no longer sufficient.

I think worth mentioning that we have major issues around stolen + CPU 
access on xe2+?

> 
> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/7513
> Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> ---
>   drivers/gpu/drm/xe/display/xe_display_bo.c | 33 ++++------------------
>   1 file changed, 6 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/display/xe_display_bo.c b/drivers/gpu/drm/xe/display/xe_display_bo.c
> index 677ae3af9ac0c..04d4204b37a53 100644
> --- a/drivers/gpu/drm/xe/display/xe_display_bo.c
> +++ b/drivers/gpu/drm/xe/display/xe_display_bo.c
> @@ -154,33 +154,12 @@ static struct drm_gem_object *xe_display_bo_fbdev_create(struct drm_device *drm,
>   	struct xe_device *xe = to_xe_device(drm);
>   	struct xe_bo *obj;
>   
> -	obj = ERR_PTR(-ENODEV);
> -
> -	if (xe_display_bo_fbdev_prefer_stolen(xe, size)) {
> -		obj = xe_bo_create_pin_map_novm(xe, xe_device_get_root_tile(xe),
> -						size,
> -						ttm_bo_type_kernel,
> -						XE_BO_FLAG_FORCE_WC |
> -						XE_BO_FLAG_STOLEN |
> -						XE_BO_FLAG_GGTT,
> -						false);
> -		if (!IS_ERR(obj))
> -			drm_info(&xe->drm, "Allocated fbdev into stolen\n");
> -		else
> -			drm_info(&xe->drm, "Allocated fbdev into stolen failed: %li\n", PTR_ERR(obj));
> -	} else {
> -		drm_info(&xe->drm, "Allocating fbdev: Stolen memory not preferred.\n");
> -	}
> -
> -	if (IS_ERR(obj)) {
> -		obj = xe_bo_create_pin_map_novm(xe, xe_device_get_root_tile(xe), size,
> -						ttm_bo_type_kernel,
> -						XE_BO_FLAG_FORCE_WC |
> -						XE_BO_FLAG_VRAM_IF_DGFX(xe_device_get_root_tile(xe)) |
> -						XE_BO_FLAG_GGTT,
> -						false);
> -	}
> -
> +	obj = xe_bo_create_pin_map_novm(xe, xe_device_get_root_tile(xe), size,
> +					ttm_bo_type_kernel,
> +					XE_BO_FLAG_FORCE_WC |
> +					XE_BO_FLAG_VRAM_IF_DGFX(xe_device_get_root_tile(xe)) |
> +					XE_BO_FLAG_GGTT,
> +					false);
>   	if (IS_ERR(obj)) {
>   		drm_err(&xe->drm, "failed to allocate framebuffer (%pe)\n", obj);
>   		return ERR_PTR(-ENOMEM);