drm/i915: Enable pipe HDR mode on ICL if only HDR planes are used

The pipe has a special HDR mode with higher precision when only
HDR planes are active. Let's use it.

Curiously this fixes the kms_color gamma/degamma tests when
using a HDR plane, which is always the case unless one hacks
the test to use an SDR plane. If one does hack the test to use
an SDR plane it does pass already.

I have no actual explanation how the output after the gamma
LUT can be different between the two modes. The way the tests
are written should mean that the output should be identical
between the solid color vs. the gradient. But clearly that
somehow doesn't hold true for the HDR planes in non-HDR pipe
mode. Anyways, as long as we stick to one type of plane the
test should produce sensible results now.

v2: s/HDR_MODE/HDR_MODE_PRECISION/ (Shashank)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190412183009.8237-2-ville.syrjala@linux.intel.com
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Tested-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 6f0a0866c8024e69da5d364f6eeb710b46058c29..f8bd637abdfb1b7f0834967523080cff63ead918 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5770,6 +5770,7 @@ enum {
 #define _PIPE_MISC_B                   0x71030
 #define   PIPEMISC_YUV420_ENABLE       (1 << 27)
 #define   PIPEMISC_YUV420_MODE_FULL_BLEND (1 << 26)
+#define   PIPEMISC_HDR_MODE_PRECISION  (1 << 23) /* icl+ */
 #define   PIPEMISC_OUTPUT_COLORSPACE_YUV  (1 << 11)
 #define   PIPEMISC_DITHER_BPC_MASK     (7 << 5)
 #define   PIPEMISC_DITHER_8_BPC                (0 << 5)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 42973456afd4c3b64dd12ac0a9a5fd767c66338a..1762a1891f1bffb7c76b36f23ee8d417d4106ca8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4099,6 +4099,9 @@ static void intel_update_pipe_config(const struct intel_crtc_state *old_crtc_sta
                        ironlake_pfit_disable(old_crtc_state);
        }
 
+       if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv))
+               bdw_set_pipemisc(new_crtc_state);
+
        if (INTEL_GEN(dev_priv) >= 11)
                icl_set_pipe_chicken(crtc);
 }
@@ -8926,6 +8929,10 @@ static void bdw_set_pipemisc(const struct intel_crtc_state *crtc_state)
                val |= PIPEMISC_YUV420_ENABLE |
                        PIPEMISC_YUV420_MODE_FULL_BLEND;
 
+       if (INTEL_GEN(dev_priv) >= 11 &&
+           (crtc_state->active_planes & ~icl_hdr_plane_mask()) == 0)
+               val |= PIPEMISC_HDR_MODE_PRECISION;
+
        I915_WRITE(PIPEMISC(crtc->pipe), val);
 }
 

diff --git a/drivers/gpu/drm/i915/intel_sprite.h b/drivers/gpu/drm/i915/intel_sprite.h
index 84be8686be16ef5146f50e11eb23733ea6d00910..500f6bffb1392aacf7568c6529b4330a957cdb7f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sprite.h
+++ b/drivers/gpu/drm/i915/intel_sprite.h
@@ -43,13 +43,17 @@ static inline bool icl_is_nv12_y_plane(enum plane_id id)
        return false;
 }
 
+static inline u8 icl_hdr_plane_mask(void)
+{
+       return BIT(PLANE_PRIMARY) |
+               BIT(PLANE_SPRITE0) | BIT(PLANE_SPRITE1);
+}
+
 static inline bool icl_is_hdr_plane(struct drm_i915_private *dev_priv,
                                    enum plane_id plane_id)
 {
-       if (INTEL_GEN(dev_priv) < 11)
-               return false;
-
-       return plane_id < PLANE_SPRITE2;
+       return INTEL_GEN(dev_priv) >= 11 &&
+               icl_hdr_plane_mask() & BIT(plane_id);
 }
 
 #endif /* __INTEL_SPRITE_H__ */