From: Ville Syrjälä ville.syrjala@linux.intel.com
Unlike SKL/GLK the ICL CSC unit suffers from a new issue where CSC_MODE arming is sticky. That is, once armed it remains armed causing the CSC coeff/offset registers to become effectively self-arming.
CSC coeff/offset registers writes no longer disarm the CSC, but fortunately register read still do. So we can use that to disarm the CSC unit once the registers for the current frame have been latched. This avoid s the self-arming behaviour from persisting into the next frame's .color_commit_noarm() call.
Cc: stable@vger.kernel.org #v5.19+ Cc: Manasi Navare navaremanasi@google.com Cc: Drew Davenport ddavenport@chromium.org Cc: Imre Deak imre.deak@intel.com Cc: Jouni Högander jouni.hogander@intel.com Fixes: d13dde449580 ("drm/i915: Split pipe+output CSC programming to noarm+arm pair") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20230320095438.17328-5-ville.s... Reviewed-by: Imre Deak imre.deak@intel.com (cherry picked from commit 92736f1b452bbb8a66bdb5b1d263ad00e04dd3b8) Signed-off-by: Jani Nikula jani.nikula@intel.com (cherry picked from commit 4d4e766f8b7dbdefa7a78e91eb9c7a29d0d818b8) --- drivers/gpu/drm/i915/display/intel_color.c | 43 +++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c index 85a38d794dd9..c9c9af795638 100644 --- a/drivers/gpu/drm/i915/display/intel_color.c +++ b/drivers/gpu/drm/i915/display/intel_color.c @@ -516,6 +516,14 @@ static void ilk_lut_12p4_pack(struct drm_color_lut *entry, u32 ldw, u32 udw)
static void icl_color_commit_noarm(const struct intel_crtc_state *crtc_state) { + /* + * Despite Wa_1406463849, ICL no longer suffers from the SKL + * DC5/PSR CSC black screen issue (see skl_color_commit_noarm()). + * Possibly due to the extra sticky CSC arming + * (see icl_color_post_update()). + * + * On TGL+ all CSC arming issues have been properly fixed. + */ icl_load_csc_matrix(crtc_state); }
@@ -617,6 +625,28 @@ static void icl_color_commit_arm(const struct intel_crtc_state *crtc_state) crtc_state->csc_mode); }
+static void icl_color_post_update(const struct intel_crtc_state *crtc_state) +{ + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); + struct drm_i915_private *i915 = to_i915(crtc->base.dev); + + /* + * Despite Wa_1406463849, ICL CSC is no longer disarmed by + * coeff/offset register *writes*. Instead, once CSC_MODE + * is armed it stays armed, even after it has been latched. + * Afterwards the coeff/offset registers become effectively + * self-arming. That self-arming must be disabled before the + * next icl_color_commit_noarm() tries to write the next set + * of coeff/offset registers. Fortunately register *reads* + * do still disarm the CSC. Naturally this must not be done + * until the previously written CSC registers have actually + * been latched. + * + * TGL+ no longer need this workaround. + */ + intel_de_read_fw(i915, PIPE_CSC_PREOFF_HI(crtc->pipe)); +} + static struct drm_property_blob * create_linear_lut(struct drm_i915_private *i915, int lut_size) { @@ -2345,10 +2375,19 @@ static const struct intel_color_funcs i9xx_color_funcs = { .read_luts = i9xx_read_luts, };
+static const struct intel_color_funcs tgl_color_funcs = { + .color_check = icl_color_check, + .color_commit_noarm = icl_color_commit_noarm, + .color_commit_arm = icl_color_commit_arm, + .load_luts = icl_load_luts, + .read_luts = icl_read_luts, +}; + static const struct intel_color_funcs icl_color_funcs = { .color_check = icl_color_check, .color_commit_noarm = icl_color_commit_noarm, .color_commit_arm = icl_color_commit_arm, + .color_post_update = icl_color_post_update, .load_luts = icl_load_luts, .read_luts = icl_read_luts, }; @@ -2440,7 +2479,9 @@ void intel_color_init_hooks(struct drm_i915_private *i915) else i915->display.funcs.color = &i9xx_color_funcs; } else { - if (DISPLAY_VER(i915) >= 11) + if (DISPLAY_VER(i915) >= 12) + i915->display.funcs.color = &tgl_color_funcs; + else if (DISPLAY_VER(i915) == 11) i915->display.funcs.color = &icl_color_funcs; else if (DISPLAY_VER(i915) == 10) i915->display.funcs.color = &glk_color_funcs;