From: Daniel Stone <daniels@collabora.com>
Date: Fri, 30 Mar 2018 15:11:28 +0100
Subject: drm/tegra: Move fbdev unmap special case
Git-commit: c34a997d033df6bbeaf5c06e9124f89bc0ecac8d
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

User framebuffers are created with either bo->pages or bo->vaddr set,
depending on whether or not an IOMMU is present. On the other hand, the
framebuffer created for fbdev emulation has a vaddr mapping made if
bo->pages is set after creation. This is set up in fbdev probe.

Remove the special case unmapping from the general-purpose framebuffer
destroy, and move it to fbdev teardown.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/tegra/fb.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -99,12 +99,8 @@ static void tegra_fb_destroy(struct drm_
 	for (i = 0; i < framebuffer->format->num_planes; i++) {
 		struct tegra_bo *bo = tegra_fb_get_plane(framebuffer, i);
 
-		if (bo) {
-			if (bo->pages)
-				vunmap(bo->vaddr);
-
+		if (bo)
 			drm_gem_object_put_unlocked(&bo->gem);
-		}
 	}
 
 	drm_framebuffer_cleanup(framebuffer);
@@ -369,8 +365,17 @@ static void tegra_fbdev_exit(struct tegr
 {
 	drm_fb_helper_unregister_fbi(&fbdev->base);
 
-	if (fbdev->fb)
+	if (fbdev->fb) {
+		struct tegra_bo *bo = tegra_fb_get_plane(fbdev->fb, 0);
+
+		/* Undo the special mapping we made in fbdev probe. */
+		if (bo && bo->pages) {
+			vunmap(bo->vaddr);
+			bo->vaddr = 0;
+		}
+
 		drm_framebuffer_remove(fbdev->fb);
+	}
 
 	drm_fb_helper_fini(&fbdev->base);
 	tegra_fbdev_free(fbdev);