1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index ffccbef962a4..a1cb020e07e5 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -604,7 +604,7 @@ static int ast_crtc_mode_set(struct drm_crtc *crtc,
                 return -EINVAL;
         ast_open_key(ast);
 
-        ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa1, 0xff, 0x04);
+        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa1, 0x06);
 
         ast_set_std_reg(crtc, adjusted_mode, &vbios_mode);
         ast_set_crtc_reg(crtc, adjusted_mode, &vbios_mode);