diff options
Diffstat (limited to 'drivers/gpu/drm/ast')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_main.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c index 3a9b4cb73f2f..48d57ab42955 100644 --- a/drivers/gpu/drm/ast/ast_main.c +++ b/drivers/gpu/drm/ast/ast_main.c @@ -387,8 +387,31 @@ static int ast_get_dram_info(struct drm_device *dev) return 0; } +enum drm_mode_status ast_mode_config_mode_valid(struct drm_device *dev, + const struct drm_display_mode *mode) +{ + static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGBA8888 */ + + struct ast_private *ast = dev->dev_private; + unsigned long fbsize, fbpages, max_fbpages; + + /* To support double buffering, a framebuffer may not + * consume more than half of the available VRAM. + */ + max_fbpages = (ast->vram_size / 2) >> PAGE_SHIFT; + + fbsize = mode->hdisplay * mode->vdisplay * max_bpp; + fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE); + + if (fbpages > max_fbpages) + return MODE_MEM; + + return MODE_OK; +} + static const struct drm_mode_config_funcs ast_mode_funcs = { - .fb_create = drm_gem_fb_create + .fb_create = drm_gem_fb_create, + .mode_valid = ast_mode_config_mode_valid, }; static u32 ast_get_vram_info(struct drm_device *dev) |