> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Friday, July 5, 2024 8:23 PM
> To: intel-gfx@lists.freedesktop.org
> Cc: intel...@lists.freedesktop.org
> Subject: [PATCH 19/20] drm/i915/fbdev: Adjust fbdev stolen mem usage heuristic
>
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> Replace the "1/2 of stolen size" fbdev fb size heuristic with something a bit
> more
> clever, that is ask the FBC code how much stolen mem it would like to have
> avaialable for its CFB use.
Looks Good to me.
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
> TODO:
> - This doesn't account for the fact that FBC's idea
> usable stolen size might differ from other users of stolen
> - Would be nice to share the code with xe, but need to
> figure out how to abstract the stolen size and
> dgpu/lmem stuff
>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_fbdev_fb.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> index 0a6445acb100..29f3241c9270 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> @@ -16,12 +16,11 @@ bool intel_fbdev_fb_prefer_stolen(struct intel_display
> *display, {
> struct drm_i915_private *i915 = to_i915(display->drm);
>
> - /*
> - * If the FB is too big, just don't use it since fbdev is not very
> - * important and we should probably use that space with FBC or other
> - * features.
> - */
> - return i915->dsm.usable_size >= size * 2;
> + if (size > i915->dsm.usable_size)
> + return false;
> +
> + /* try to ensure FBC has enough stolen to do its job well */
> + return i915->dsm.usable_size - size >=
> +intel_fbc_preferred_cfb_size(&i915->display);
> }
>
> struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
> --
> 2.44.2
