[PATCH] drm/amdgpu: assign dpms for amdgpu_vkms_crtc_helper_funcs

[Asher Song]

In drm_helper_disable_unused_functions(), when !crtc->enable is false, a NULL pointer crtc_funcs->dpms may occur. To avoid this, assign dpms for amdgpu_vkms_crtc_helper_funcs.

 Call Trace:
  __drm_helper_disable_unused_functions+0xac/0xe0 [drm_kms_helper]
  drm_helper_disable_unused_functions+0x38/0x60 [drm_kms_helper]
  amdgpu_fbdev_init+0xf6/0x100 [amdgpu]
  amdgpu_device_init+0x13d4/0x1f10 [amdgpu]

Fixes: ba5317109d0ce ("drm/amdgpu: create amdgpu_vkms (v4)")
Signed-off-by: Asher Song <Asher.Song at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 26 ++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 50bdc39733aa..9cfe479c4c97 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -156,7 +156,33 @@ static void amdgpu_vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 	}
 }
 
+static void amdgpu_vkms_crtc_dpms(struct drm_crtc *crtc, int mode)
+{
+	struct drm_device *dev = crtc->dev;
+	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
+	unsigned type;
+
+	switch (mode) {
+	case DRM_MODE_DPMS_ON:
+		amdgpu_crtc->enabled = true;
+		/* Make sure VBLANK interrupts are still enabled */
+		type = amdgpu_display_crtc_idx_to_irq_type(adev,
+						amdgpu_crtc->crtc_id);
+		amdgpu_irq_update(adev, &adev->crtc_irq, type);
+		drm_crtc_vblank_on(crtc);
+		break;
+	case DRM_MODE_DPMS_STANDBY:
+	case DRM_MODE_DPMS_SUSPEND:
+	case DRM_MODE_DPMS_OFF:
+		drm_crtc_vblank_off(crtc);
+		amdgpu_crtc->enabled = false;
+		break;
+	}
+}
+
 static const struct drm_crtc_helper_funcs amdgpu_vkms_crtc_helper_funcs = {
+	.dpms = amdgpu_vkms_crtc_dpms,
 	.atomic_flush	= amdgpu_vkms_crtc_atomic_flush,
 	.atomic_enable	= amdgpu_vkms_crtc_atomic_enable,
 	.atomic_disable	= amdgpu_vkms_crtc_atomic_disable,
-- 
2.25.1