drm/i915/fbc: Allow FBC to recompress after a 3D workload on i85x/i865
Normally i85x/i865 3D activity will block FBC until a 2D blit
occurs. I suppose this was meant to avoid recompression while
3D activity is still going on but the frame hasn't yet been
presented. Unfortunately that also means that a page flipped
3D workload will permanently block FBC even if it only renders
a single frame and then does nothing.
Since we are using software render tracking anyway we might as
well flip the chicken bit so that 3D does not block FBC. This
will avoid the permament FBC blockage in the aforemention use
case, but thanks to the software tracking the compressor will
not disturb 3D rendering activity.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702153723.24327-5-ville.syrjala@linux.intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9d6536a..03590d2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2827,6 +2827,7 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
#define VLV_GU_CTL0 _MMIO(VLV_DISPLAY_BASE + 0x2030)
#define VLV_GU_CTL1 _MMIO(VLV_DISPLAY_BASE + 0x2034)
#define SCPD0 _MMIO(0x209c) /* 915+ only */
+#define SCPD_FBC_IGNORE_3D (1 << 6)
#define CSTATE_RENDER_CLOCK_GATE_DISABLE (1 << 5)
#define GEN2_IER _MMIO(0x20a0)
#define GEN2_IIR _MMIO(0x20a4)
