[Intel-gfx] [PATCH v5 06/11] drm/i915/dsb: functions to enable/disable DSB engine.

Animesh Manna animesh.manna at intel.com
Sat Sep 7 11:07:30 UTC 2019


DSB will be used for performance improvement for some special scenario.
DSB engine will be enabled based on need and after completion of its work
will be disabled. Api added for enable/disable operation by using DSB_CTRL
register.

v1: Initial version.
v2: POSTING_READ added after writing control register. (Shashank)

Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dsb.c | 42 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_reg.h          |  1 +
 2 files changed, 43 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index 2c8415518c65..56bf41b00f62 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -26,6 +26,48 @@ static inline bool is_dsb_busy(struct intel_dsb *dsb)
 	return DSB_STATUS & I915_READ(DSB_CTRL(pipe, dsb->id));
 }
 
+static inline bool intel_dsb_enable_engine(struct intel_dsb *dsb)
+{
+	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	u32 dsb_ctrl;
+
+	dsb_ctrl = I915_READ(DSB_CTRL(pipe, dsb->id));
+
+	if (DSB_STATUS & dsb_ctrl) {
+		DRM_DEBUG_KMS("DSB engine is busy.\n");
+		return false;
+	}
+
+	dsb_ctrl |= DSB_ENABLE;
+	I915_WRITE(DSB_CTRL(pipe, dsb->id), dsb_ctrl);
+
+	POSTING_READ(DSB_CTRL(pipe, dsb->id));
+	return true;
+}
+
+static inline bool intel_dsb_disable_engine(struct intel_dsb *dsb)
+{
+	struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	u32 dsb_ctrl;
+
+	dsb_ctrl = I915_READ(DSB_CTRL(pipe, dsb->id));
+
+	if (DSB_STATUS & dsb_ctrl) {
+		DRM_DEBUG_KMS("DSB engine is busy.\n");
+		return false;
+	}
+
+	dsb_ctrl &= ~DSB_ENABLE;
+	I915_WRITE(DSB_CTRL(pipe, dsb->id), dsb_ctrl);
+
+	POSTING_READ(DSB_CTRL(pipe, dsb->id));
+	return true;
+}
+
 struct intel_dsb *
 intel_dsb_get(struct intel_crtc *crtc)
 {
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a3099f712ae6..2df01386e3de 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -11681,6 +11681,7 @@ enum skl_power_gate {
 #define DSBSL_INSTANCE(pipe, id)	(_DSBSL_INSTANCE_BASE + \
 					 (pipe) * 0x1000 + (id) * 100)
 #define DSB_CTRL(pipe, id)		_MMIO(DSBSL_INSTANCE(pipe, id) + 0x8)
+#define   DSB_ENABLE			(1 << 31)
 #define   DSB_STATUS			(1 << 0)
 
 #endif /* _I915_REG_H_ */
-- 
2.22.0



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