drm/amd/display: Disable VUpdate interrupt for DCN hardware

[Why]

On DCN hardware, the crtc_high_irq handler makes vupdate_high_irq
handler redundant.

All the vupdate handler does is handle vblank events, and update vrr
for DCE hw (excluding VEGA, more on that later). As far as usermode is
concerned. vstartup happens close enough to vupdate on DCN that it can
be considered the "same". Handling vblank and updating vrr at vstartup
effectively replaces vupdate on DCN.

Vega is a bit special. Like DCN, the VRR registers on Vega are
double-buffered, and swapped at vupdate. But Unlike DCN, it lacks a
vstartup interrupt. This means we can't quite remove the vupdate handler
for it, since delayed user events due to vrr are sent off there.

[How]

Remove registration of vupdate interrupt handler for DCN. Disable
vupdate interrupt if asic family DCN, enable otherwise.
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -2241,34 +2241,6 @@ static int dcn10_register_irq_handlers(struct amdgpu_device *adev)
 				dm_dcn_crtc_high_irq, c_irq_params);
 	}
 
-	/* Use VUPDATE_NO_LOCK interrupt on DCN, which seems to correspond to
-	 * the regular VUPDATE interrupt on DCE. We want DC_IRQ_SOURCE_VUPDATEx
-	 * to trigger at end of each vblank, regardless of state of the lock,
-	 * matching DCE behaviour.
-	 */
-	for (i = DCN_1_0__SRCID__OTG0_IHC_V_UPDATE_NO_LOCK_INTERRUPT;
-	     i <= DCN_1_0__SRCID__OTG0_IHC_V_UPDATE_NO_LOCK_INTERRUPT + adev->mode_info.num_crtc - 1;
-	     i++) {
-		r = amdgpu_irq_add_id(adev, SOC15_IH_CLIENTID_DCE, i, &adev->vupdate_irq);
-
-		if (r) {
-			DRM_ERROR("Failed to add vupdate irq id!\n");
-			return r;
-		}
-
-		int_params.int_context = INTERRUPT_HIGH_IRQ_CONTEXT;
-		int_params.irq_source =
-			dc_interrupt_to_irq_source(dc, i, 0);
-
-		c_irq_params = &adev->dm.vupdate_params[int_params.irq_source - DC_IRQ_SOURCE_VUPDATE1];
-
-		c_irq_params->adev = adev;
-		c_irq_params->irq_src = int_params.irq_source;
-
-		amdgpu_dm_irq_register_interrupt(adev, &int_params,
-				dm_vupdate_high_irq, c_irq_params);
-	}
-
 	/* Use GRPH_PFLIP interrupt */
 	for (i = DCN_1_0__SRCID__HUBP0_FLIP_INTERRUPT;
 			i <= DCN_1_0__SRCID__HUBP0_FLIP_INTERRUPT + adev->mode_info.num_crtc - 1;
@@ -4178,6 +4150,10 @@ static inline int dm_set_vupdate_irq(struct drm_crtc *crtc, bool enable)
 	struct amdgpu_device *adev = crtc->dev->dev_private;
 	int rc;
 
+	/* Do not set vupdate for DCN hardware */
+	if (adev->family > AMDGPU_FAMILY_AI)
+		return 0;
+
 	irq_source = IRQ_TYPE_VUPDATE + acrtc->otg_inst;
 
 	rc = dc_interrupt_set(adev->dm.dc, irq_source, enable) ? 0 : -EBUSY;