drm/i915: Split pipe+output CSC programming to noarm+arm pair

Move most of the pipe+output CSC programming to the
.color_commit_noarm() hook which runs before vblank evasion.
Only PIPE_CSC_MODE (the arming register) needs to remain in
inside the critical section.

A test case that just updates the CTM in a loop produces
the following i915_update_info numbers on ilk (w/o lockdep):
old                                 new
Updates: 10012			    Updates: 10008
       |			    	   |
   1us |**			       1us |**********
       |*************		    	   |*************
   4us |*********		       4us |*
       |*			    	   |**
  16us |			      16us |
       |			    	   |
  66us |			      66us |
       |			    	   |
 262us |			     262us |
       |			    	   |
   1ms |			       1ms |
       |			    	   |
   4ms |			       4ms |
       |			    	   |
  17ms |			      17ms |
       |			    	   |
Min update: 1345ns		    Min update: 1268ns
Max update: 16672ns		    Max update: 15656ns
Average update: 3914ns		    Average update: 2185ns
Overruns > 100us: 0		    Overruns > 100us: 0

And here is tgl (forced to update both pipe CSC and
output CSC, and with lockdep enabled):
old                                 new
Updates: 10012			    Updates: 10012
       |			    	   |
   1us |			       1us |
       |			    	   |
   4us |*			       4us |**
       |**			    	   |**********
  16us |*************		      16us |*************
       |*			    	   |
  66us |			      66us |
       |			    	   |
 262us |			     262us |
       |			    	   |
   1ms |			       1ms |
       |			    	   |
   4ms |			       4ms |
       |			    	   |
  17ms |			      17ms |
       |			    	   |
Min update: 5204ns		    Min update: 5176ns
Max update: 176038ns		    Max update: 186685ns
Average update: 23931ns		    Average update: 16654ns
Overruns > 250us: 0		    Overruns > 250us: 0

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220224165103.15682-5-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index df775c6..34128c9 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -346,15 +346,11 @@ static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
                                    ilk_csc_coeff_identity,
                                    ilk_csc_off_zero);
        }
-
-       intel_de_write_fw(dev_priv, PIPE_CSC_MODE(crtc->pipe),
-                         crtc_state->csc_mode);
 }
 
 static void icl_load_csc_matrix(const struct intel_crtc_state *crtc_state)
 {
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
-       struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 
        if (crtc_state->hw.ctm) {
                u16 coeff[9];
@@ -373,9 +369,6 @@ static void icl_load_csc_matrix(const struct intel_crtc_state *crtc_state)
                                      ilk_csc_coeff_limited_range,
                                      ilk_csc_postoff_limited_range);
        }
-
-       intel_de_write_fw(dev_priv, PIPE_CSC_MODE(crtc->pipe),
-                         crtc_state->csc_mode);
 }
 
 static void chv_load_cgm_csc(struct intel_crtc *crtc,
@@ -500,6 +493,16 @@ static void icl_lut_multi_seg_pack(struct drm_color_lut *entry, u32 ldw, u32 udw
                                    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, ldw);
 }
 
+static void icl_color_commit_noarm(const struct intel_crtc_state *crtc_state)
+{
+       icl_load_csc_matrix(crtc_state);
+}
+
+static void ilk_color_commit_noarm(const struct intel_crtc_state *crtc_state)
+{
+       ilk_load_csc_matrix(crtc_state);
+}
+
 static void i9xx_color_commit_arm(const struct intel_crtc_state *crtc_state)
 {
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
@@ -525,7 +528,8 @@ static void ilk_color_commit_arm(const struct intel_crtc_state *crtc_state)
        val |= PIPECONF_GAMMA_MODE(crtc_state->gamma_mode);
        intel_de_write(dev_priv, PIPECONF(pipe), val);
 
-       ilk_load_csc_matrix(crtc_state);
+       intel_de_write_fw(dev_priv, PIPE_CSC_MODE(pipe),
+                         crtc_state->csc_mode);
 }
 
 static void hsw_color_commit_arm(const struct intel_crtc_state *crtc_state)
@@ -536,7 +540,8 @@ static void hsw_color_commit_arm(const struct intel_crtc_state *crtc_state)
        intel_de_write(dev_priv, GAMMA_MODE(crtc->pipe),
                       crtc_state->gamma_mode);
 
-       ilk_load_csc_matrix(crtc_state);
+       intel_de_write_fw(dev_priv, PIPE_CSC_MODE(crtc->pipe),
+                         crtc_state->csc_mode);
 }
 
 static void skl_color_commit_arm(const struct intel_crtc_state *crtc_state)
@@ -560,10 +565,8 @@ static void skl_color_commit_arm(const struct intel_crtc_state *crtc_state)
        intel_de_write(dev_priv, GAMMA_MODE(crtc->pipe),
                       crtc_state->gamma_mode);
 
-       if (DISPLAY_VER(dev_priv) >= 11)
-               icl_load_csc_matrix(crtc_state);
-       else
-               ilk_load_csc_matrix(crtc_state);
+       intel_de_write_fw(dev_priv, PIPE_CSC_MODE(crtc->pipe),
+                         crtc_state->csc_mode);
 }
 
 static void i9xx_load_lut_8(struct intel_crtc *crtc,
@@ -2170,6 +2173,7 @@ static const struct intel_color_funcs i9xx_color_funcs = {
 
 static const struct intel_color_funcs icl_color_funcs = {
        .color_check = icl_color_check,
+       .color_commit_noarm = icl_color_commit_noarm,
        .color_commit_arm = skl_color_commit_arm,
        .load_luts = icl_load_luts,
        .read_luts = icl_read_luts,
@@ -2177,6 +2181,7 @@ static const struct intel_color_funcs icl_color_funcs = {
 
 static const struct intel_color_funcs glk_color_funcs = {
        .color_check = glk_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = skl_color_commit_arm,
        .load_luts = glk_load_luts,
        .read_luts = glk_read_luts,
@@ -2184,6 +2189,7 @@ static const struct intel_color_funcs glk_color_funcs = {
 
 static const struct intel_color_funcs skl_color_funcs = {
        .color_check = ivb_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = skl_color_commit_arm,
        .load_luts = bdw_load_luts,
        .read_luts = NULL,
@@ -2191,6 +2197,7 @@ static const struct intel_color_funcs skl_color_funcs = {
 
 static const struct intel_color_funcs bdw_color_funcs = {
        .color_check = ivb_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = hsw_color_commit_arm,
        .load_luts = bdw_load_luts,
        .read_luts = NULL,
@@ -2198,6 +2205,7 @@ static const struct intel_color_funcs bdw_color_funcs = {
 
 static const struct intel_color_funcs hsw_color_funcs = {
        .color_check = ivb_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = hsw_color_commit_arm,
        .load_luts = ivb_load_luts,
        .read_luts = NULL,
@@ -2205,6 +2213,7 @@ static const struct intel_color_funcs hsw_color_funcs = {
 
 static const struct intel_color_funcs ivb_color_funcs = {
        .color_check = ivb_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = ilk_color_commit_arm,
        .load_luts = ivb_load_luts,
        .read_luts = NULL,
@@ -2212,6 +2221,7 @@ static const struct intel_color_funcs ivb_color_funcs = {
 
 static const struct intel_color_funcs ilk_color_funcs = {
        .color_check = ilk_color_check,
+       .color_commit_noarm = ilk_color_commit_noarm,
        .color_commit_arm = ilk_color_commit_arm,
        .load_luts = ilk_load_luts,
        .read_luts = ilk_read_luts,