[PATCH v3.1] drm/xe/display: Fix fbdev GGTT mapping handling.

[Maarten Lankhorst <dev@lankhorst.se>]

The fbdev vma is a normal unrotated VMA, so add ane explicit check
before re-using.

When re-using, we have to restore the GGTT mapping on resume, so add
some code to do that too.

Fixes: 67a98f7e27ba ("drm/xe/display: Re-use display vmas when possible")
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
 drivers/gpu/drm/xe/display/xe_display.c |  6 +++++-
 drivers/gpu/drm/xe/display/xe_fb_pin.c  | 24 +++++++++++++++++++++++-
 drivers/gpu/drm/xe/display/xe_fb_pin.h  | 13 +++++++++++++
 3 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 drivers/gpu/drm/xe/display/xe_fb_pin.h

diff --git a/drivers/gpu/drm/xe/display/xe_display.c b/drivers/gpu/drm/xe/display/xe_display.c
index 02a413a073824..999f25a562c19 100644
--- a/drivers/gpu/drm/xe/display/xe_display.c
+++ b/drivers/gpu/drm/xe/display/xe_display.c
@@ -30,6 +30,7 @@
 #include "intel_hotplug.h"
 #include "intel_opregion.h"
 #include "skl_watermark.h"
+#include "xe_fb_pin.h"
 #include "xe_module.h"
 
 /* Xe device functions */
@@ -492,8 +493,11 @@ void xe_display_pm_resume(struct xe_device *xe)
 		intel_display_driver_enable_user_access(display);
 	}
 
-	if (has_display(xe))
+	if (has_display(xe)) {
+		xe_fb_pin_resume(xe);
+
 		intel_hpd_poll_disable(xe);
+	}
 
 	intel_opregion_resume(display);
 
diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c b/drivers/gpu/drm/xe/display/xe_fb_pin.c
index 11a6b996d739b..dee1f6531c849 100644
--- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
+++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
@@ -12,6 +12,7 @@
 #include "intel_fbdev.h"
 #include "xe_bo.h"
 #include "xe_device.h"
+#include "xe_fb_pin.h"
 #include "xe_ggtt.h"
 #include "xe_pm.h"
 
@@ -398,7 +399,8 @@ static bool reuse_vma(struct intel_plane_state *new_plane_state,
 		goto found;
 	}
 
-	if (fb == intel_fbdev_framebuffer(xe->display.fbdev.fbdev)) {
+	if (fb == intel_fbdev_framebuffer(xe->display.fbdev.fbdev) &&
+	    new_plane_state->view.gtt.type == I915_GTT_VIEW_NORMAL) {
 		vma = intel_fbdev_vma_pointer(xe->display.fbdev.fbdev);
 		if (vma)
 			goto found;
@@ -444,6 +446,26 @@ void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
 	old_plane_state->ggtt_vma = NULL;
 }
 
+void xe_fb_pin_resume(struct xe_device *xe)
+{
+	struct xe_ggtt *ggtt = xe_device_get_root_tile(xe)->mem.ggtt;
+	struct i915_vma *vma = intel_fbdev_vma_pointer(xe->display.fbdev.fbdev);
+	struct xe_bo *bo;
+
+	if (!vma)
+		return;
+
+	bo = vma->bo;
+
+	mutex_lock(&ggtt->lock);
+	for (u32 x = 0; x < bo->ttm.base.size; x += XE_PAGE_SIZE) {
+		u64 pte = ggtt->pt_ops->pte_encode_bo(bo, x, xe->pat.idx[XE_CACHE_NONE]);
+
+		ggtt->pt_ops->ggtt_set_pte(ggtt, vma->node->base.start + x, pte);
+	}
+	mutex_unlock(&ggtt->lock);
+}
+
 /*
  * For Xe introduce dummy intel_dpt_create which just return NULL,
  * intel_dpt_destroy which does nothing, and fake intel_dpt_ofsset returning 0;
diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.h b/drivers/gpu/drm/xe/display/xe_fb_pin.h
new file mode 100644
index 0000000000000..39d48ff637002
--- /dev/null
+++ b/drivers/gpu/drm/xe/display/xe_fb_pin.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef _XE_FB_PIN_H_
+#define _XE_FB_PIN_H_
+
+struct xe_device;
+
+void xe_fb_pin_resume(struct xe_device *xe);
+
+#endif /* _XE_FB_PIN_H_ */
-- 
2.47.1