drm/xe/display: Make display suspend/resume work on discrete

We should unpin before evicting all memory, and repin after GT resume.
This way, we preserve the contents of the framebuffers, and won't hang
on resume due to migration engine not being restored yet.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: stable@vger.kernel.org # v6.8+
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240806105044.596842-3-maarten.lankhorst@linux.intel.com
Signed-off-by: Maarten Lankhorst,,, <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/xe/display/xe_display.c

@@ -287,6 +287,27 @@ static bool suspend_to_idle(void)
 	return false;
 }
 
+static void xe_display_flush_cleanup_work(struct xe_device *xe)
+{
+	struct intel_crtc *crtc;
+
+	for_each_intel_crtc(&xe->drm, crtc) {
+		struct drm_crtc_commit *commit;
+
+		spin_lock(&crtc->base.commit_lock);
+		commit = list_first_entry_or_null(&crtc->base.commit_list,
+						  struct drm_crtc_commit, commit_entry);
+		if (commit)
+			drm_crtc_commit_get(commit);
+		spin_unlock(&crtc->base.commit_lock);
+
+		if (commit) {
+			wait_for_completion(&commit->cleanup_done);
+			drm_crtc_commit_put(commit);
+		}
+	}
+}
+
 void xe_display_pm_suspend(struct xe_device *xe, bool runtime)
 {
 	struct intel_display *display = &xe->display;
@@ -308,6 +329,8 @@ void xe_display_pm_suspend(struct xe_device *xe, bool runtime)
 	if (!runtime)
 		intel_display_driver_suspend(xe);
 
+	xe_display_flush_cleanup_work(xe);
+
 	intel_dp_mst_suspend(xe);
 
 	intel_hpd_cancel_work(xe);

drivers/gpu/drm/xe/xe_pm.c

@@ -93,13 +93,13 @@ int xe_pm_suspend(struct xe_device *xe)
 	for_each_gt(gt, xe, id)
 		xe_gt_suspend_prepare(gt);
 
+	xe_display_pm_suspend(xe, false);
+
 	/* FIXME: Super racey... */
 	err = xe_bo_evict_all(xe);
 	if (err)
 		goto err;
 
-	xe_display_pm_suspend(xe, false);
-
 	for_each_gt(gt, xe, id) {
 		err = xe_gt_suspend(gt);
 		if (err) {
@@ -154,11 +154,11 @@ int xe_pm_resume(struct xe_device *xe)
 
 	xe_irq_resume(xe);
 
-	xe_display_pm_resume(xe, false);
-
 	for_each_gt(gt, xe, id)
 		xe_gt_resume(gt);
 
+	xe_display_pm_resume(xe, false);
+
 	err = xe_bo_restore_user(xe);
 	if (err)
 		goto err;
@@ -367,10 +367,11 @@ int xe_pm_runtime_suspend(struct xe_device *xe)
 	mutex_unlock(&xe->mem_access.vram_userfault.lock);
 
 	if (xe->d3cold.allowed) {
+		xe_display_pm_suspend(xe, true);
+
 		err = xe_bo_evict_all(xe);
 		if (err)
 			goto out;
-		xe_display_pm_suspend(xe, true);
 	}
 
 	for_each_gt(gt, xe, id) {