With the patch, we reserve 2x 16 KiB at the high end of video memory,
with each frame aligned to an 8-byte boundary. The remaining memory is
available for GEM VRAM buffer objects.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/ast/ast_ttm.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_ttm.c b/drivers/gpu/drm/ast/ast_ttm.c
index fad34106083a..8e6a1d8917d0 100644
--- a/drivers/gpu/drm/ast/ast_ttm.c
+++ b/drivers/gpu/drm/ast/ast_ttm.c
@@ -35,13 +35,20 @@
int ast_mm_init(struct ast_private *ast)
{
+ unsigned long cursor_size;
struct drm_vram_mm *vmm;
int ret;
struct drm_device *dev = ast->dev;
- vmm = drm_vram_helper_alloc_mm(
- dev, pci_resource_start(dev->pdev, 0),
- ast->vram_size);
+ /* At the high end of video memory, we reserve space for
+ * two cursor images. The cursor plane uses this memory to
+ * store a double-buffered image of the current cursor.
+ */
+ cursor_size = roundup((AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE),
+ PAGE_SIZE) * AST_DEFAULT_HWC_NUM;
+
+ vmm = drm_vram_helper_alloc_mm(dev, pci_resource_start(dev->pdev, 0),
+ ast->vram_size - cursor_size);
if (IS_ERR(vmm)) {
ret = PTR_ERR(vmm);
DRM_ERROR("Error initializing VRAM MM; %d\n", ret);
--
2.23.0
