drm/amd/display: In VRR mode, do DRM core vblank handling at end of vblank. (v2)

In VRR mode, proper vblank/pageflip timestamps can only be computed
after the display scanout position has left front-porch. Therefore
delay calls to drm_crtc_handle_vblank(), and thereby calls to
drm_update_vblank_count() and pageflip event delivery, to after the
end of front-porch when in VRR mode.

We add a new vupdate irq, which triggers at the end of the vupdate
interval, ie. at the end of vblank, and calls the core vblank handler
function. The new irq handler is not executed in standard non-VRR
mode, so vblank handling for fixed refresh rate mode is identical
to the past implementation.

v2: Implement feedback by Nicholas and Paul Menzel.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

4 files changed, 47 insertions, 13 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/irq/dce110/irq_service_dce110.c b/drivers/gpu/drm/amd/display/dc/irq/dce110/irq_service_dce110.c
index afe0876fe6f8..86987f5e8bd5 100644
--- a/drivers/gpu/drm/amd/display/dc/irq/dce110/irq_service_dce110.c
+++ b/drivers/gpu/drm/amd/display/dc/irq/dce110/irq_service_dce110.c
@@ -81,6 +81,11 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 	.ack = NULL
 };
 
+static const struct irq_source_info_funcs vupdate_irq_info_funcs = {
+	.set = NULL,
+	.ack = NULL
+};
+
 #define hpd_int_entry(reg_num)\
 	[DC_IRQ_SOURCE_HPD1 + reg_num] = {\
 		.enable_reg = mmHPD ## reg_num ## _DC_HPD_INT_CONTROL,\
@@ -137,7 +142,7 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 		CRTC_V_UPDATE_INT_STATUS__CRTC_V_UPDATE_INT_CLEAR_MASK,\
 		.ack_value =\
 		CRTC_V_UPDATE_INT_STATUS__CRTC_V_UPDATE_INT_CLEAR_MASK,\
-		.funcs = &vblank_irq_info_funcs\
+		.funcs = &vupdate_irq_info_funcs\
 	}
 
 #define vblank_int_entry(reg_num)\
diff --git a/drivers/gpu/drm/amd/display/dc/irq/dce120/irq_service_dce120.c b/drivers/gpu/drm/amd/display/dc/irq/dce120/irq_service_dce120.c
index 1ea7256ec89b..750ba0ab4106 100644
--- a/drivers/gpu/drm/amd/display/dc/irq/dce120/irq_service_dce120.c
+++ b/drivers/gpu/drm/amd/display/dc/irq/dce120/irq_service_dce120.c
@@ -84,6 +84,11 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 	.ack = NULL
 };
 
+static const struct irq_source_info_funcs vupdate_irq_info_funcs = {
+	.set = NULL,
+	.ack = NULL
+};
+
 #define BASE_INNER(seg) \
 	DCE_BASE__INST0_SEG ## seg
 
@@ -140,7 +145,7 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 		IRQ_REG_ENTRY(CRTC, reg_num,\
 			CRTC_INTERRUPT_CONTROL, CRTC_V_UPDATE_INT_MSK,\
 			CRTC_V_UPDATE_INT_STATUS, CRTC_V_UPDATE_INT_CLEAR),\
-		.funcs = &vblank_irq_info_funcs\
+		.funcs = &vupdate_irq_info_funcs\
 	}
 
 #define vblank_int_entry(reg_num)\
diff --git a/drivers/gpu/drm/amd/display/dc/irq/dce80/irq_service_dce80.c b/drivers/gpu/drm/amd/display/dc/irq/dce80/irq_service_dce80.c
index 8a2066c313fe..de218fe84a43 100644
--- a/drivers/gpu/drm/amd/display/dc/irq/dce80/irq_service_dce80.c
+++ b/drivers/gpu/drm/amd/display/dc/irq/dce80/irq_service_dce80.c
@@ -84,6 +84,10 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 	.ack = NULL
 };
 
+static const struct irq_source_info_funcs vupdate_irq_info_funcs = {
+	.set = NULL,
+	.ack = NULL
+};
 
 #define hpd_int_entry(reg_num)\
 	[DC_IRQ_SOURCE_INVALID + reg_num] = {\
@@ -142,7 +146,7 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 		CRTC_V_UPDATE_INT_STATUS__CRTC_V_UPDATE_INT_CLEAR_MASK,\
 		.ack_value =\
 		CRTC_V_UPDATE_INT_STATUS__CRTC_V_UPDATE_INT_CLEAR_MASK,\
-		.funcs = &vblank_irq_info_funcs\
+		.funcs = &vupdate_irq_info_funcs\
 	}
 
 #define vblank_int_entry(reg_num)\
diff --git a/drivers/gpu/drm/amd/display/dc/irq/dcn10/irq_service_dcn10.c b/drivers/gpu/drm/amd/display/dc/irq/dcn10/irq_service_dcn10.c
index e04ae49243f6..10ac6deff5ff 100644
--- a/drivers/gpu/drm/amd/display/dc/irq/dcn10/irq_service_dcn10.c
+++ b/drivers/gpu/drm/amd/display/dc/irq/dcn10/irq_service_dcn10.c
@@ -56,6 +56,18 @@ enum dc_irq_source to_dal_irq_source_dcn10(
 		return DC_IRQ_SOURCE_VBLANK5;
 	case DCN_1_0__SRCID__DC_D6_OTG_VSTARTUP:
 		return DC_IRQ_SOURCE_VBLANK6;
+	case DCN_1_0__SRCID__OTG0_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE1;
+	case DCN_1_0__SRCID__OTG1_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE2;
+	case DCN_1_0__SRCID__OTG2_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE3;
+	case DCN_1_0__SRCID__OTG3_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE4;
+	case DCN_1_0__SRCID__OTG4_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE5;
+	case DCN_1_0__SRCID__OTG5_IHC_V_UPDATE_NO_LOCK_INTERRUPT:
+		return DC_IRQ_SOURCE_VUPDATE6;
 	case DCN_1_0__SRCID__HUBP0_FLIP_INTERRUPT:
 		return DC_IRQ_SOURCE_PFLIP1;
 	case DCN_1_0__SRCID__HUBP1_FLIP_INTERRUPT:
@@ -153,6 +165,11 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 	.ack = NULL
 };
 
+static const struct irq_source_info_funcs vupdate_no_lock_irq_info_funcs = {
+	.set = NULL,
+	.ack = NULL
+};
+
 #define BASE_INNER(seg) \
 	DCE_BASE__INST0_SEG ## seg
 
@@ -203,12 +220,15 @@ static const struct irq_source_info_funcs vblank_irq_info_funcs = {
 		.funcs = &pflip_irq_info_funcs\
 	}
 
-#define vupdate_int_entry(reg_num)\
+/* vupdate_no_lock_int_entry maps to DC_IRQ_SOURCE_VUPDATEx, to match semantic
+ * of DCE's DC_IRQ_SOURCE_VUPDATEx.
+ */
+#define vupdate_no_lock_int_entry(reg_num)\
 	[DC_IRQ_SOURCE_VUPDATE1 + reg_num] = {\
 		IRQ_REG_ENTRY(OTG, reg_num,\
-			OTG_GLOBAL_SYNC_STATUS, VUPDATE_INT_EN,\
-			OTG_GLOBAL_SYNC_STATUS, VUPDATE_EVENT_CLEAR),\
-		.funcs = &vblank_irq_info_funcs\
+			OTG_GLOBAL_SYNC_STATUS, VUPDATE_NO_LOCK_INT_EN,\
+			OTG_GLOBAL_SYNC_STATUS, VUPDATE_NO_LOCK_EVENT_CLEAR),\
+		.funcs = &vupdate_no_lock_irq_info_funcs\
 	}
 
 #define vblank_int_entry(reg_num)\
@@ -315,12 +335,12 @@ irq_source_info_dcn10[DAL_IRQ_SOURCES_NUMBER] = {
 	dc_underflow_int_entry(6),
 	[DC_IRQ_SOURCE_DMCU_SCP] = dummy_irq_entry(),
 	[DC_IRQ_SOURCE_VBIOS_SW] = dummy_irq_entry(),
-	vupdate_int_entry(0),
-	vupdate_int_entry(1),
-	vupdate_int_entry(2),
-	vupdate_int_entry(3),
-	vupdate_int_entry(4),
-	vupdate_int_entry(5),
+	vupdate_no_lock_int_entry(0),
+	vupdate_no_lock_int_entry(1),
+	vupdate_no_lock_int_entry(2),
+	vupdate_no_lock_int_entry(3),
+	vupdate_no_lock_int_entry(4),
+	vupdate_no_lock_int_entry(5),
 	vblank_int_entry(0),
 	vblank_int_entry(1),
 	vblank_int_entry(2),