[PATCH v3 02/21] drm/i915/display: Enable RM timeout detection

[Balasubramani Vivekanandan]

From: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>

Enable RM timeout interrupt to detect any hang during display engine
register access.
Current default timeout is 2ms.

v2:
* Modified the IP version check to apply on all versions starting from
  14
* Improved the print log

Bspec: 50110
CC: Suraj Kandpal <suraj.kandpal at intel.com>
CC: Matt Roper <matthew.d.roper at intel.com>
CC: Jani Nikula <jani.nikula at linux.intel.com>
Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>
Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_irq.c | 10 ++++++++++
 drivers/gpu/drm/i915/i915_reg.h                  |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c b/drivers/gpu/drm/i915/display/intel_display_irq.c
index c337e0597541..9c65e9e32fca 100644
--- a/drivers/gpu/drm/i915/display/intel_display_irq.c
+++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
@@ -852,6 +852,13 @@ gen8_de_misc_irq_handler(struct drm_i915_private *dev_priv, u32 iir)
 {
 	bool found = false;
 
+	if (iir & GEN8_DE_RM_TIMEOUT) {
+		u32 val = intel_uncore_read(&dev_priv->uncore,
+				RMTIMEOUTREG_CAPTURE);
+		drm_warn(&dev_priv->drm, "Register access timeout for offset = 0x%x\n", val);
+		found = true;
+	}
+
 	if (DISPLAY_VER(dev_priv) >= 14) {
 		if (iir & (XELPDP_PMDEMAND_RSP |
 			   XELPDP_PMDEMAND_RSPTOUT_ERR)) {
@@ -1667,6 +1674,9 @@ void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 			de_port_masked |= DSI0_TE | DSI1_TE;
 	}
 
+	if (DISPLAY_VER(dev_priv) >= 14)
+		de_misc_masked |= GEN8_DE_RM_TIMEOUT;
+
 	de_pipe_enables = de_pipe_masked |
 		GEN8_PIPE_VBLANK |
 		gen8_de_pipe_underrun_mask(dev_priv) |
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3f34efcd7d6c..a8cdabd07b04 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4225,6 +4225,8 @@
 #define RM_TIMEOUT		_MMIO(0x42060)
 #define  MMIO_TIMEOUT_US(us)	((us) << 0)
 
+#define RMTIMEOUTREG_CAPTURE	_MMIO(0x420e0)
+
 /* interrupts */
 #define DE_MASTER_IRQ_CONTROL   (1 << 31)
 #define DE_SPRITEB_FLIP_DONE    (1 << 29)
@@ -4411,6 +4413,7 @@
 #define GEN8_DE_MISC_IMR _MMIO(0x44464)
 #define GEN8_DE_MISC_IIR _MMIO(0x44468)
 #define GEN8_DE_MISC_IER _MMIO(0x4446c)
+#define  GEN8_DE_RM_TIMEOUT		REG_BIT(29)
 #define  XELPDP_PMDEMAND_RSPTOUT_ERR	REG_BIT(27)
 #define  GEN8_DE_MISC_GSE		REG_BIT(27)
 #define  GEN8_DE_EDP_PSR		REG_BIT(19)
-- 
2.25.1