drm/ast: Store each HW cursor offset after pinning the rsp BO

As HW cursor BOs never move, we can store the offset in VRAM in the
cursor-plane's HWC state. This removes the last possible source of
runtime errors from atomic_update.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210209134632.12157-10-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 22193cf..e82ab86 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -108,6 +108,7 @@ struct ast_cursor_plane {
        struct {
                struct drm_gem_vram_object *gbo;
                struct dma_buf_map map;
+               u64 off;
        } hwc[AST_DEFAULT_HWC_NUM];
 
        unsigned int next_hwc_index;

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index b9b9bad..e8de86d 100644 (file)
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -823,26 +823,19 @@ ast_cursor_plane_helper_atomic_update(struct drm_plane *plane,
        struct drm_plane_state *state = plane->state;
        struct drm_framebuffer *fb = state->fb;
        struct ast_private *ast = to_ast_private(plane->dev);
-       struct drm_device *dev = &ast->base;
-       struct drm_gem_vram_object *gbo =
-               ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].gbo;
+       u64 dst_off =
+               ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].off;
        unsigned int offset_x, offset_y;
-       s64 off;
        struct dma_buf_map map;
        u16 x, y;
        u8 x_offset, y_offset;
        u8 __iomem *dst;
        u8 __iomem *sig;
 
-       gbo = ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].gbo;
        map = ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].map;
 
        if (state->fb != old_state->fb) {
-               /* A new cursor image was installed. */
-               off = drm_gem_vram_offset(gbo);
-               if (drm_WARN_ON_ONCE(dev, off < 0))
-                       return; /* Bug: we didn't pin the cursor HW BO to VRAM. */
-               ast_set_cursor_base(ast, off);
+               ast_set_cursor_base(ast, dst_off);
 
                ++ast_cursor_plane->next_hwc_index;
                ast_cursor_plane->next_hwc_index %= ARRAY_SIZE(ast_cursor_plane->hwc);
@@ -931,6 +924,7 @@ static int ast_cursor_plane_init(struct ast_private *ast)
        struct drm_gem_vram_object *gbo;
        struct dma_buf_map map;
        int ret;
+       s64 off;
 
        /*
         * Allocate backing storage for cursors. The BOs are permanently
@@ -952,8 +946,14 @@ static int ast_cursor_plane_init(struct ast_private *ast)
                ret = drm_gem_vram_vmap(gbo, &map);
                if (ret)
                        goto err_drm_gem_vram_unpin;
+               off = drm_gem_vram_offset(gbo);
+               if (off < 0) {
+                       ret = off;
+                       goto err_drm_gem_vram_vunmap;
+               }
                ast_cursor_plane->hwc[i].gbo = gbo;
                ast_cursor_plane->hwc[i].map = map;
+               ast_cursor_plane->hwc[i].off = off;
        }
 
        /*
@@ -979,6 +979,7 @@ err_hwc:
                --i;
                gbo = ast_cursor_plane->hwc[i].gbo;
                map = ast_cursor_plane->hwc[i].map;
+err_drm_gem_vram_vunmap:
                drm_gem_vram_vunmap(gbo, &map);
 err_drm_gem_vram_unpin:
                drm_gem_vram_unpin(gbo);