drm/ast: Remove cursor double buffering

Update the cursor image via damage handling in-place. The cursor's
double buffering has no visible effect on the output, so remove it.

Done in preparation of switching ast to GEM SHMEM helpers. Removing
double buffering will allow us to use the same data structure for
primary and cursor plane.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221013112923.769-5-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 2e44b971c3a6b1fdc5fded85927435ae68206e62..12294c74d0fc1befb04407058cf128f72ab9d4ac 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -96,8 +96,6 @@ enum ast_tx_chip {
 #define AST_HWC_SIZE           (AST_MAX_HWC_WIDTH * AST_MAX_HWC_HEIGHT * 2)
 #define AST_HWC_SIGNATURE_SIZE 32
 
-#define AST_DEFAULT_HWC_NUM    2
-
 /* define for signature structure */
 #define AST_HWC_SIGNATURE_CHECKSUM     0x00
 #define AST_HWC_SIGNATURE_SizeX                0x04
@@ -110,13 +108,9 @@ enum ast_tx_chip {
 struct ast_cursor_plane {
        struct drm_plane base;
 
-       struct {
-               struct drm_gem_vram_object *gbo;
-               struct iosys_map map;
-               u64 off;
-       } hwc[AST_DEFAULT_HWC_NUM];
-
-       unsigned int next_hwc_index;
+       struct drm_gem_vram_object *gbo;
+       struct iosys_map map;
+       u64 off;
 };
 
 static inline struct ast_cursor_plane *

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 059e4906507d416e357b3d6bb4a03c7e8b17a697..06ee79ec86f1fe8d045dc78e4459c912484a891c 100644 (file)
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -837,10 +837,8 @@ ast_cursor_plane_helper_atomic_update(struct drm_plane *plane,
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(new_state);
        struct drm_framebuffer *fb = new_state->fb;
        struct ast_private *ast = to_ast_private(plane->dev);
-       struct iosys_map dst_map =
-               ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].map;
-       u64 dst_off =
-               ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].off;
+       struct iosys_map dst_map = ast_cursor_plane->map;
+       u64 dst_off = ast_cursor_plane->off;
        struct iosys_map src_map = shadow_plane_state->data[0];
        unsigned int offset_x, offset_y;
        u16 x, y;
@@ -860,13 +858,9 @@ ast_cursor_plane_helper_atomic_update(struct drm_plane *plane,
 
        ast_update_cursor_image(dst, src, fb->width, fb->height);
 
-       if (new_state->fb != old_state->fb) {
+       if (new_state->fb != old_state->fb)
                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);
-       }
-
        /*
         * Update location in HWC signature and registers.
         */
@@ -917,17 +911,12 @@ static const struct drm_plane_helper_funcs ast_cursor_plane_helper_funcs = {
 static void ast_cursor_plane_destroy(struct drm_plane *plane)
 {
        struct ast_cursor_plane *ast_cursor_plane = to_ast_cursor_plane(plane);
-       size_t i;
-       struct drm_gem_vram_object *gbo;
-       struct iosys_map map;
+       struct drm_gem_vram_object *gbo = ast_cursor_plane->gbo;
+       struct iosys_map map = ast_cursor_plane->map;
 
-       for (i = 0; i < ARRAY_SIZE(ast_cursor_plane->hwc); ++i) {
-               gbo = ast_cursor_plane->hwc[i].gbo;
-               map = ast_cursor_plane->hwc[i].map;
-               drm_gem_vram_vunmap(gbo, &map);
-               drm_gem_vram_unpin(gbo);
-               drm_gem_vram_put(gbo);
-       }
+       drm_gem_vram_vunmap(gbo, &map);
+       drm_gem_vram_unpin(gbo);
+       drm_gem_vram_put(gbo);
 
        drm_plane_cleanup(plane);
 }
@@ -944,7 +933,7 @@ static int ast_cursor_plane_init(struct ast_private *ast)
        struct drm_device *dev = &ast->base;
        struct ast_cursor_plane *ast_cursor_plane = &ast->cursor_plane;
        struct drm_plane *cursor_plane = &ast_cursor_plane->base;
-       size_t size, i;
+       size_t size;
        struct drm_gem_vram_object *gbo;
        struct iosys_map map;
        int ret;
@@ -957,29 +946,27 @@ static int ast_cursor_plane_init(struct ast_private *ast)
 
        size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE);
 
-       for (i = 0; i < ARRAY_SIZE(ast_cursor_plane->hwc); ++i) {
-               gbo = drm_gem_vram_create(dev, size, 0);
-               if (IS_ERR(gbo)) {
-                       ret = PTR_ERR(gbo);
-                       goto err_hwc;
-               }
-               ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM |
-                                           DRM_GEM_VRAM_PL_FLAG_TOPDOWN);
-               if (ret)
-                       goto err_drm_gem_vram_put;
-               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;
+       gbo = drm_gem_vram_create(dev, size, 0);
+       if (IS_ERR(gbo))
+               return PTR_ERR(gbo);
+
+       ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM |
+                                   DRM_GEM_VRAM_PL_FLAG_TOPDOWN);
+       if (ret)
+               goto err_drm_gem_vram_put;
+       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->gbo = gbo;
+       ast_cursor_plane->map = map;
+       ast_cursor_plane->off = off;
+
        /*
         * Create the cursor plane. The plane's destroy callback will release
         * the backing storages' BO memory.
@@ -992,24 +979,18 @@ static int ast_cursor_plane_init(struct ast_private *ast)
                                       NULL, DRM_PLANE_TYPE_CURSOR, NULL);
        if (ret) {
                drm_err(dev, "drm_universal_plane failed(): %d\n", ret);
-               goto err_hwc;
+               goto err_drm_gem_vram_vunmap;
        }
        drm_plane_helper_add(cursor_plane, &ast_cursor_plane_helper_funcs);
 
        return 0;
 
-err_hwc:
-       while (i) {
-               --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);
+       drm_gem_vram_vunmap(gbo, &map);
 err_drm_gem_vram_unpin:
-               drm_gem_vram_unpin(gbo);
+       drm_gem_vram_unpin(gbo);
 err_drm_gem_vram_put:
-               drm_gem_vram_put(gbo);
-       }
+       drm_gem_vram_put(gbo);
        return ret;
 }