> -----Original Message-----
> From: Nikula, Jani <jani.nikula@xxxxxxxxx>
> Sent: Wednesday, August 17, 2022 3:26 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Nikula, Jani <jani.nikula@xxxxxxxxx>; Ville Syrjälä
> <ville.syrjala@xxxxxxxxxxxxxxx>; Kahola, Mika <mika.kahola@xxxxxxxxx>
> Subject: [PATCH] drm/i915/mtl: Introduce FBC B
>
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> MTL introduces a second FBC engine. The two FBC engines can operate entirely
> independently, FBC A serving pipe A and FBC B serving pipe B.
>
> The one place where things might go a bit wrong is the CFB allocation from
> stolen. We might have to consider some change to the allocation strategy to
> have a better chance of both engines being able to allocate its CFB. Maybe FBC
> A should allocate bottom up and FBC B top down, or something? For the
> moment the allocation strategy is DRM_MM_INSERT_BEST for both.
>
> Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_fbc.h | 1 +
> drivers/gpu/drm/i915/i915_pci.c | 3 ++-
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.h
> b/drivers/gpu/drm/i915/display/intel_fbc.h
> index db60143295ec..4adb98afe6ff 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.h
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.h
> @@ -19,6 +19,7 @@ struct intel_plane_state;
>
> enum intel_fbc_id {
> INTEL_FBC_A,
> + INTEL_FBC_B,
>
> I915_MAX_FBCS,
> };
> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
> index 9fd788e147a3..d8446bb25d5e 100644
> --- a/drivers/gpu/drm/i915/i915_pci.c
> +++ b/drivers/gpu/drm/i915/i915_pci.c
> @@ -1111,7 +1111,8 @@ static const struct intel_device_info pvc_info = {
> #define XE_LPDP_FEATURES \
> XE_LPD_FEATURES, \
> .display.ver = 14, \
> - .display.has_cdclk_crawl = 1
> + .display.has_cdclk_crawl = 1, \
> + .display.fbc_mask = BIT(INTEL_FBC_A) | BIT(INTEL_FBC_B)
>
> __maybe_unused
> static const struct intel_device_info mtl_info = {
> --
> 2.34.1
