drm/i915/display/debugfs: New entry "DRRS capable" to i915_drrs_status

If the connected panel supports both DRRS & PSR, driver gives preference
to PSR ("DRRS enabled: no"). Even though the hardware supports DRRS,
IGT treats ("DRRS enabled: yes") as not capable.

Introduce a new entry "DRRS capable" to debugfs i915_drrs_status, so
that IGT will read the DRRS capability as "DRRS capable: yes".
Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem@intel.com>
Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221111223.2313692-1-bhanuprakash.modem@intel.com

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

@@ -299,6 +299,7 @@ void intel_drrs_crtc_init(struct intel_crtc *crtc)
 static int intel_drrs_debugfs_status_show(struct seq_file *m, void *unused)
 {
 	struct intel_crtc *crtc = m->private;
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
 	const struct intel_crtc_state *crtc_state;
 	int ret;
 
@@ -310,6 +311,11 @@ static int intel_drrs_debugfs_status_show(struct seq_file *m, void *unused)
 
 	mutex_lock(&crtc->drrs.mutex);
 
+	seq_printf(m, "DRRS capable: %s\n",
+		   str_yes_no(crtc_state->has_drrs ||
+			      HAS_DOUBLE_BUFFERED_M_N(i915) ||
+			      intel_cpu_transcoder_has_m2_n2(i915, crtc_state->cpu_transcoder)));
+
 	seq_printf(m, "DRRS enabled: %s\n",
 		   str_yes_no(crtc_state->has_drrs));