drm/radeon/kms: Don't overwrite crtc_gen_cntl or crtc_gen_cntl2

Don't overwritte  crtc_gen_cntl or crtc_gen_cntl2 or we may loose the
cursor. This especialy happen when changing video mode. Fix bugs:
https://bugzilla.redhat.com/show_bug.cgi?id=529146

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
index 6634769c9ac2..c5c5c022e8c0 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
@@ -647,12 +647,8 @@ static bool radeon_set_crtc_timing(struct drm_crtc *crtc, struct drm_display_mod
                 uint32_t crtc2_gen_cntl;
                 uint32_t disp2_merge_cntl;
 
-                /* check to see if TV DAC is enabled for another crtc and keep it enabled */
-                if (RREG32(RADEON_CRTC2_GEN_CNTL) & RADEON_CRTC2_CRT2_ON)
-                        crtc2_gen_cntl = RADEON_CRTC2_CRT2_ON;
-                else
-                        crtc2_gen_cntl = 0;
-
+                /* if TV DAC is enabled for another crtc and keep it enabled */
+                crtc2_gen_cntl = RREG32(RADEON_CRTC2_GEN_CNTL) & 0x00718080;
                 crtc2_gen_cntl |= ((format << 8)
                                    | RADEON_CRTC2_VSYNC_DIS
                                    | RADEON_CRTC2_HSYNC_DIS
@@ -681,7 +677,8 @@ static bool radeon_set_crtc_timing(struct drm_crtc *crtc, struct drm_display_mod
                 uint32_t crtc_ext_cntl;
                 uint32_t disp_merge_cntl;
 
-                crtc_gen_cntl = (RADEON_CRTC_EXT_DISP_EN
+                crtc_gen_cntl = RREG32(RADEON_CRTC_GEN_CNTL) & 0x00718000;
+                crtc_gen_cntl |= (RADEON_CRTC_EXT_DISP_EN
                                  | (format << 8)
                                  | RADEON_CRTC_DISP_REQ_EN_B
                                  | ((mode->flags & DRM_MODE_FLAG_DBLSCAN)