drm/i915/psr/skl+: Print information about what caused a PSR exit

This will be helpful to debug what hardware is actually tracking
and causing PSR to exit.

BSpec: 7721

v4:
- Using _MMIO_TRANS2() in PSR_EVENT
- Cleaning events before printing

Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180425212334.21109-2-jose.souza@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -4095,6 +4095,29 @@ enum {
 #define   EDP_PSR2_IDLE_FRAME_MASK	0xf
 #define   EDP_PSR2_IDLE_FRAME_SHIFT	0
 
+#define _PSR_EVENT_TRANS_A			0x60848
+#define _PSR_EVENT_TRANS_B			0x61848
+#define _PSR_EVENT_TRANS_C			0x62848
+#define _PSR_EVENT_TRANS_D			0x63848
+#define _PSR_EVENT_TRANS_EDP			0x6F848
+#define PSR_EVENT(trans)			_MMIO_TRANS2(trans, _PSR_EVENT_TRANS_A)
+#define  PSR_EVENT_PSR2_WD_TIMER_EXPIRE		(1 << 17)
+#define  PSR_EVENT_PSR2_DISABLED		(1 << 16)
+#define  PSR_EVENT_SU_DIRTY_FIFO_UNDERRUN	(1 << 15)
+#define  PSR_EVENT_SU_CRC_FIFO_UNDERRUN		(1 << 14)
+#define  PSR_EVENT_GRAPHICS_RESET		(1 << 12)
+#define  PSR_EVENT_PCH_INTERRUPT		(1 << 11)
+#define  PSR_EVENT_MEMORY_UP			(1 << 10)
+#define  PSR_EVENT_FRONT_BUFFER_MODIFY		(1 << 9)
+#define  PSR_EVENT_WD_TIMER_EXPIRE		(1 << 8)
+#define  PSR_EVENT_PIPE_REGISTERS_UPDATE	(1 << 6)
+#define  PSR_EVENT_REGISTER_UPDATE		(1 << 5)
+#define  PSR_EVENT_HDCP_ENABLE			(1 << 4)
+#define  PSR_EVENT_KVMR_SESSION_ENABLE		(1 << 3)
+#define  PSR_EVENT_VBI_ENABLE			(1 << 2)
+#define  PSR_EVENT_LPSP_MODE_EXIT		(1 << 1)
+#define  PSR_EVENT_PSR_DISABLE			(1 << 0)
+
 #define EDP_PSR2_STATUS			_MMIO(0x6f940)
 #define EDP_PSR2_STATUS_STATE_MASK     (0xf<<28)
 #define EDP_PSR2_STATUS_STATE_SHIFT    28

drivers/gpu/drm/i915/intel_psr.c

@@ -125,6 +125,43 @@ void intel_psr_irq_control(struct drm_i915_private *dev_priv, bool debug)
 	I915_WRITE(EDP_PSR_IMR, ~mask);
 }
 
+static void psr_event_print(u32 val, bool psr2_enabled)
+{
+	DRM_DEBUG_KMS("PSR exit events: 0x%x\n", val);
+	if (val & PSR_EVENT_PSR2_WD_TIMER_EXPIRE)
+		DRM_DEBUG_KMS("\tPSR2 watchdog timer expired\n");
+	if ((val & PSR_EVENT_PSR2_DISABLED) && psr2_enabled)
+		DRM_DEBUG_KMS("\tPSR2 disabled\n");
+	if (val & PSR_EVENT_SU_DIRTY_FIFO_UNDERRUN)
+		DRM_DEBUG_KMS("\tSU dirty FIFO underrun\n");
+	if (val & PSR_EVENT_SU_CRC_FIFO_UNDERRUN)
+		DRM_DEBUG_KMS("\tSU CRC FIFO underrun\n");
+	if (val & PSR_EVENT_GRAPHICS_RESET)
+		DRM_DEBUG_KMS("\tGraphics reset\n");
+	if (val & PSR_EVENT_PCH_INTERRUPT)
+		DRM_DEBUG_KMS("\tPCH interrupt\n");
+	if (val & PSR_EVENT_MEMORY_UP)
+		DRM_DEBUG_KMS("\tMemory up\n");
+	if (val & PSR_EVENT_FRONT_BUFFER_MODIFY)
+		DRM_DEBUG_KMS("\tFront buffer modification\n");
+	if (val & PSR_EVENT_WD_TIMER_EXPIRE)
+		DRM_DEBUG_KMS("\tPSR watchdog timer expired\n");
+	if (val & PSR_EVENT_PIPE_REGISTERS_UPDATE)
+		DRM_DEBUG_KMS("\tPIPE registers updated\n");
+	if (val & PSR_EVENT_REGISTER_UPDATE)
+		DRM_DEBUG_KMS("\tRegister updated\n");
+	if (val & PSR_EVENT_HDCP_ENABLE)
+		DRM_DEBUG_KMS("\tHDCP enabled\n");
+	if (val & PSR_EVENT_KVMR_SESSION_ENABLE)
+		DRM_DEBUG_KMS("\tKVMR session enabled\n");
+	if (val & PSR_EVENT_VBI_ENABLE)
+		DRM_DEBUG_KMS("\tVBI enabled\n");
+	if (val & PSR_EVENT_LPSP_MODE_EXIT)
+		DRM_DEBUG_KMS("\tLPSP mode exited\n");
+	if ((val & PSR_EVENT_PSR_DISABLE) && !psr2_enabled)
+		DRM_DEBUG_KMS("\tPSR disabled\n");
+}
+
 void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
 {
 	u32 transcoders = BIT(TRANSCODER_EDP);
@@ -152,6 +189,14 @@ void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
 			dev_priv->psr.last_exit = time_ns;
 			DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
 				      transcoder_name(cpu_transcoder));
+
+			if (INTEL_GEN(dev_priv) >= 9) {
+				u32 val = I915_READ(PSR_EVENT(cpu_transcoder));
+				bool psr2_enabled = dev_priv->psr.psr2_enabled;
+
+				I915_WRITE(PSR_EVENT(cpu_transcoder), val);
+				psr_event_print(val, psr2_enabled);
+			}
 		}
 	}
 }