drm/i915/psr: Allow setting I915_PSR_DEBUG_SU_REGION_ET_DISABLE via debugfs

Currently setting I915_PSR_DEBUG_SU_REGION_ET_DISABLE (0x20) via psr_debug
debugfs interface is not allowed. This patch allows it.

v3:
  - ensure psr is disabled/enabled if enable_psr2_su_region_et changes
  - remove extra space
v2: ensure that fastset is performed when the bit changes
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240529093849.1016172-6-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_psr.c

@@ -2494,12 +2494,15 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
 		 * - PSR disabled in new state
 		 * - All planes will go inactive
 		 * - Changing between PSR versions
+		 * - Region Early Transport changing
 		 * - Display WA #1136: skl, bxt
 		 */
 		needs_to_disable |= intel_crtc_needs_modeset(new_crtc_state);
 		needs_to_disable |= !new_crtc_state->has_psr;
 		needs_to_disable |= !new_crtc_state->active_planes;
 		needs_to_disable |= new_crtc_state->has_sel_update != psr->sel_update_enabled;
+		needs_to_disable |= new_crtc_state->enable_psr2_su_region_et !=
+			psr->su_region_et_enabled;
 		needs_to_disable |= DISPLAY_VER(i915) < 11 &&
 			new_crtc_state->wm_level_disabled;
 
@@ -2735,10 +2738,12 @@ int intel_psr_debug_set(struct intel_dp *intel_dp, u64 val)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	const u32 mode = val & I915_PSR_DEBUG_MODE_MASK;
-	u32 old_mode;
+	const u32 disable_bits = val & I915_PSR_DEBUG_SU_REGION_ET_DISABLE;
+	u32 old_mode, old_disable_bits;
 	int ret;
 
-	if (val & ~(I915_PSR_DEBUG_IRQ | I915_PSR_DEBUG_MODE_MASK) ||
+	if (val & ~(I915_PSR_DEBUG_IRQ | I915_PSR_DEBUG_SU_REGION_ET_DISABLE |
+		    I915_PSR_DEBUG_MODE_MASK) ||
 	    mode > I915_PSR_DEBUG_ENABLE_SEL_FETCH) {
 		drm_dbg_kms(&dev_priv->drm, "Invalid debug mask %llx\n", val);
 		return -EINVAL;
@@ -2749,6 +2754,8 @@ int intel_psr_debug_set(struct intel_dp *intel_dp, u64 val)
 		return ret;
 
 	old_mode = intel_dp->psr.debug & I915_PSR_DEBUG_MODE_MASK;
+	old_disable_bits = intel_dp->psr.debug &
+		I915_PSR_DEBUG_SU_REGION_ET_DISABLE;
 	intel_dp->psr.debug = val;
 
 	/*
@@ -2760,7 +2767,7 @@ int intel_psr_debug_set(struct intel_dp *intel_dp, u64 val)
 
 	mutex_unlock(&intel_dp->psr.lock);
 
-	if (old_mode != mode)
+	if (old_mode != mode || old_disable_bits != disable_bits)
 		ret = intel_psr_fastset_force(dev_priv);
 
 	return ret;