[PATCH v2 2/3] drm/radeon: Restore GART table contents after pinning it in VRAM

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

The GART table BO has to be moved out of VRAM for suspend/resume. Any
updates to the GART table during that time were silently dropped without
this change. This caused GPU lockups on resume in some cases, see the bug
reports referenced below.

This might also make GPU reset more robust in some cases, as we no longer
rely on the GART table in VRAM being preserved across the GPU
lockup/reset.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85204
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86267
Cc: stable at vger.kernel.org
Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---

v2: Add logic to radeon_gart_table_vram_pin directly instead of reinstating
    radeon_gart_restore function

 drivers/gpu/drm/radeon/radeon_gart.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index a530932..0c8c739 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -163,6 +163,14 @@ int radeon_gart_table_vram_pin(struct radeon_device *rdev)
 	r = radeon_bo_kmap(rdev->gart.robj, &rdev->gart.ptr);
 	if (r)
 		radeon_bo_unpin(rdev->gart.robj);
+	else {
+		int i;
+
+		for (i = 0; i < rdev->gart.num_gpu_pages; i++)
+			radeon_gart_set_page(rdev, i, rdev->gart.pages_entry[i]);
+		mb();
+		radeon_gart_tlb_flush(rdev);
+	}
 	radeon_bo_unreserve(rdev->gart.robj);
 	rdev->gart.table_addr = gpu_addr;
 	return r;
-- 
2.1.4