drm/amdgpu/dce8: Re-set VBLANK interrupt state when enabling a CRTC

Something (ATOM BIOS?) seems to be clobbering the LB_INTERRUPT_MASK
register while the CRTC is off, which caused e.g. glxgears or
gnome-shell to hang after a modeset.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 08387dfd98a7..cc050a329c49 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -2566,6 +2566,7 @@ static void dce_v8_0_crtc_dpms(struct drm_crtc *crtc, int mode)
         struct drm_device *dev = crtc->dev;
         struct amdgpu_device *adev = dev->dev_private;
         struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
+        unsigned type;
 
         switch (mode) {
         case DRM_MODE_DPMS_ON:
@@ -2574,6 +2575,9 @@ static void dce_v8_0_crtc_dpms(struct drm_crtc *crtc, int mode)
                 dce_v8_0_vga_enable(crtc, true);
                 amdgpu_atombios_crtc_blank(crtc, ATOM_DISABLE);
                 dce_v8_0_vga_enable(crtc, false);
+                /* Make sure VBLANK interrupt is still enabled */
+                type = amdgpu_crtc_idx_to_irq_type(adev, amdgpu_crtc->crtc_id);
+                amdgpu_irq_update(adev, &adev->crtc_irq, type);
                 drm_vblank_post_modeset(dev, amdgpu_crtc->crtc_id);
                 dce_v8_0_crtc_load_lut(crtc);
                 break;