[PATCH 1/2] drm/amdgpu: reapply "fix start calculation in amdgpu_vram_mgr_new""

[Christian König]

This re-applys commit 5e3f1e7729ec7a99e145e9d8ed58963d86cdfb98.

The original problem this was reverted for was found and the correct fix
will be merged to drm-misc-next-fixes.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 49e4092f447f..51d9d3a4456c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 			list_splice_tail(trim_list, &vres->blocks);
 	}
 
-	list_for_each_entry(block, &vres->blocks, link)
-		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
+	vres->base.start = 0;
+	list_for_each_entry(block, &vres->blocks, link) {
+		unsigned long start;
 
-	block = amdgpu_vram_mgr_first_block(&vres->blocks);
-	if (!block) {
-		r = -EINVAL;
-		goto error_fini;
-	}
+		start = amdgpu_vram_mgr_block_start(block) +
+			amdgpu_vram_mgr_block_size(block);
+		start >>= PAGE_SHIFT;
 
-	vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
+		if (start > vres->base.num_pages)
+			start -= vres->base.num_pages;
+		else
+			start = 0;
+		vres->base.start = max(vres->base.start, start);
+
+		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
+	}
 
 	if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
 		vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
-- 
2.25.1